MODERN  CHEMISTRY  AND  ITS 
WONDERS 


Photo,  E.N.A. 


A  FUTURE  CENTRE  OF  CHEMICAL  INDUSTRY. 
Kaieteur  Falls. 


The  most  wonderful  in  the  world.  With  a  height  of  741  feet  and  a  breadth  of  over 
350  feet  and  set  in  majestic  scenery  in  the  Potaro  River  in  British  Guiana,  this  fall 
could  supply  2|  million  horse-power,  and  will,  no  doubt,  in  the  near  future  be  a  great 
industrial  centre. 


MODERN   CHEMISTRY 
AND  ITS  WONDERS 

A  POPULAR  ACCOUNT  OF  SOME  OF  THE  MORE 

REMARKABLE  RECENT  ADVANCES  IN 

CHEMICAL  SCIENCE  FOR 

GENERAL  READERS 

BY 

GEOFFREY   MARTIN,  D.Sc.,  PH.D. 

FIRST-CLASS  HONOURSMAN  IN  CHEMISTRY  OF  LONDON  UNIVERSITY 

AUTHOR  OF  "TRIUMPHS  AND  WONDERS  OF  MODERN  CHEMISTRY,"  "PRACTICAL 

CHEMISTRY,"  "INDUSTRIAL  CHEMISTRY,"  "THE  HALOGENS,"  "CHEMICAL 

LECTURE  DIAGRAMS,"   "RESEARCHES   ON   THE  AFFINITIES   OF   THE 
ELEMENTS,"  ETC.   ETC. 


Yet  I  doubt  not  through  the  ages  one  increasing  purpose  runs, 
And  the  thoughts  of  men  are  widened  with  the  process  of  the  suns. 

TBNNYSON 


ILLUSTRATED 


NEW    YORK 

D.  VAN   NOSTRAND   COMPANY 

TWENTY-FIVE   PARK   PLACE 

1915 


PRINTED  IN  GREAT  BRITAIN 


MO':?-     *J   ''• 


PREFACE 

MY  recently  published  book  Triumphs  and  Wonders  of 
Modern  Chemistry  met  with  such  an  enthusiastic  welcome 
by  the  chemical  reading  public,  having  run  through  two 
editions  and  been  translated  into  Russian  in  the  compara- 
tively short  time  which  has  elapsed  since  publication, 
that  when  my  publishers  approached  me  with  the  request 
to  write  a  companion  volume  to  that  work,  treating  of 
matters  omitted  for  want  of  space  in  the  first  book,  I 
gladly  acceded  to  their  proposal.  The  present  book  is 
the  result.  The  treatment  is  popular,  technicalities  being 
avoided  as  much  as  possible.  However,  in  it  I  suppose 
the  reader  to  be  familiar  with  the  ordinary  conceptions 
of  chemistry,  such  as  have  already  been  explained  in  a 
popular  manner  in  the  first  book.  The  book  is  not  in- 
tended for  students  wishing  to  study  for  one  or  other 
of  the  innumerable  examinations  of  our  somewhat  chaotic 
educational  system.  Rather  it  is  intended  to  interest  the 
cultured  general  reader  in  some  of  the  really  wonderful 
achievements  of  scientific  chemistry.  The  subjects  chosen 
include  both  technical  and  pure  scientific  advances,  with 
which  the  writer  has  had  special  opportunities  of  be- 
coming conversant. 

The  reception  accorded  to  the  first  volume,  not  only 
in  the  reviews  but  also  fn  the  numerous  letters  which  have 
reached  me  from  practically  all  parts  of  the  world,  has 
convinced  the  writer  that  the  work  met  a  real  want  and 
that  a  considerable  demand  exists  for  a  book  of  this  type. 
There  exists  a  wide  public  interested  in  scientific  problems, 

3573Si 


vi      MODERN    CHEMISTRY    AND    ITS    WONDERS 

who  have  neither  the  leisure  nor  the  inclination  to  master 
the  technicalities  and  enter  into  the  minutiae  of  the  regular 
text-book  of  chemistry — the  latter  type  of  book  also 
labours  under  the  disadvantage  that  only  such  things  can 
be  discussed  therein  as  are  likely  to  have  academic  ex- 
amination questions  set  on  them. 

In  addition  to  interesting  general  readers,  the  book 
may  possibly  prove  useful  to  popular  lecturers  and  chem- 
istry teachers  in  need  of  interesting  illustrative  facts  for 
their  routine  chemical  classes. 

Popular  books  on  science,  although  depreciated  by 
professional  scientists,  yet  serve  an  extremely  useful  pur- 
pose in  bringing  home  to  the  mass  of  the  people  the 
enormous  importance  of  Science  to  the  State. 

The  greatest  care  has  been  taken  to  keep  the  subject 
matter  thoroughly  up-to-date.  Much  of  the  material  here 
appears  in  book  form  for  the  first  time.  In  every  case 
the  most  recent  authorities,  not  only  English  but  foreign 
as  well,  have  been  consulted. 

No  one  authority  has  been  slavishly  followed,  but  an 
endeavour  has  been  made  to  put  every  fact  in  a  fresh 
and  original  way. 

Consequently  the  reader  will  find  many  old  problems 
presented  afresh  in  a  novel  form  and  treated  on  lines 
different  from  those  usually  adopted  in  the  ordinary 
chemical  text-book.  By  such  means  I  hope  to  bring 
the  reader  into  immediate  contact  with  the  thoughts  of 
the  great  leaders  of  science,  whose  ideas,  usually  buried 
away  in  the  transactions  of  learned  societies,  are  inac- 
cessible to  all  but  the  specialist. 

Seeing  that  this  book  is  being  issued  during  our 
struggle  with  the  Germans,  it  will  not  be  irrelevant  to 
mention  that  for  many  years  chemists  have  been  urging 
that  in  any  war  that  we  might  have  with  Germany,  our 
enemies  would  be  all  the  more  formidable  because  of 


PREFACE  vii 

their  high  scientific  education  and  attainments.  The 
scientists  of  this  country  have  been  advocating  that  there 
should  be  national  encouragement  and  support  of  the 
useful  kind  of  scientific  man,  that  our  manufacturers 
should  employ  men  who  have  scientific  qualifications, 
and  that  into  the  ranks  of  those  who  govern  us  there 
should  be  introduced  a  much  larger  leaven  of  men  of 
science.  Unhappily  this  advice  fell  upon  deaf  ears.  A 
war  with  Germany  is,  in  a  great  measure,  a  contest  be- 
tween chemists,  and  British  chemists  believe  that  if  the 
government  would  have  listened  to  them,  the  Germans 
would  have  been  beaten  in  the  early  stages  of  the  great 
war,  and  that  thousands  upon  thousands  of  lives  would 
have  been  saved  ;  they  say  that  in  the  Autumn  of  the 
year  1914,  Germany  was  saved  from  a  crushing  defeat 
because  she  had  possessed  the  sense  to  encourage  her 
chemists.  In  these  pages,  the  Author  hopes  that  he  will 
be  able  to  reveal  the  marvels  of  chemistry,  and  at  the 
same  time  to  make  plain  the  importance  of  scientific 
studies  in  national  affairs. 

My  best  thanks  are  due  to  Mr.  W.  P.  Dreaper,  Editor 
of  the  Chemical  World,  who  allowed  me  to  reproduce  my 
article  on  "  Metallic  Firestones/'which  first  appeared  in  that 
journal  under  the  title  "  The  Pyrophoric  Alloy  Industry," 
and  also  gave  me  permission  to  reproduce  a  picture  of  the 
cultivation  of  Sugar  Beet. 

To  Dr.  Lander,  Professor  of  Chemistry  at  the  Royal 
Veterinary  College,  London,  I  am  indebted  for  several 
curious  and  interesting  facts  which  do  not  seem  to  be 
generally  known. 

To  Dr.  Henry  Sand,  of  Nottingham  University 
College,  I  am  indebted  for  illustrations  of  the  apparatus 
used  in  Electro-chemical  Analysis — a  subject  which  has 
been  much  advanced  by  his  researches. 

To  Sir  Henry  Roscoe,  F.R.S.,  I  am  indebted  for  leave 


viii     MODERN   CHEMISTRY   AND    ITS    WONDERS 

to  quote  from  his  interesting  Life  and  Experiences.  To  Mr. 
G.  W.  Clough,  B.Sc.,  I  am  indebted  for  several  valuable 
suggestions.  To  the  late  Professor  R.  K.  Duncan  and 
to  his  publishers,  the  A.  S.  Barnes  Co.  of  New  York  and 
Messrs.  Hodder  &  Stoughton  of  London,  I  must  express 
my  best  thanks  for  leave  to  quote  from  The  New 
Knowledge. 

Messrs.  Crookes  &  Reynolds'  Diagram  of  Atomic 
Weights  is  reproduced  by  kind  permission  of  the  British 
Association.  The  picture  of  the  Pennycraig  Explosion 
is  reproduced  by  kind  permission  of  the  South  Wales 
Institute  of  Engineers  from  Professor  Gallaway's  Colliery 
Explosions.  The  illustration  of  the  "  Will-o'-the-Wisp  "  is  re- 
produced by  permission  of  Messrs.  W.  &  R.  Chambers, 
Ltd.,  from  The  Gallery  of  Nature.  The  two  illustrations  of 
Asphalt  Digging  in  Trinidad  are  reproduced  by  permission 
ot  the  Institution  of  Mining  Engineers.  The  illustrations 
of  a  Malt  House  and  Mash  Tuns  are  reproduced  by  per- 
mission of  Messrs.  A.  Guiness  &  Co.,  Ltd.  The  curve  of 
Atomic  Volumes  is  reproduced  by  permission  of  Messrs. 
Blackie  &  Son,  Ltd.,  from  Caven  and  Lander's  Systematic 
Chemistry.  The  Chemical  Society  of  London  gave  per- 
mission to  reproduce  the  illustrations  of  Dr.  Sand's 
apparatus  for  Electro-chemical  Analysis.  Professor  Joly 
of  Dublin  and  his  publishers,  Messrs.  Constable  &  Co., 
Ltd.,  kindly  gave  me  permission  both  to  quote  from  and 
to  use  some  illustrations  of  the  book  Radio- Activity  and 
Geology.  The  Editor  of  Cassiers  Magazine  gave  me 
leave  not  only  to  quote  some  extracts  from  the  journal, 
but  also  to  use  some  of  the  illustrations.  To  Messrs. 
Fred.  Bayer  &  Co.  I  am  indebted  for  the  photograph  of 
the  picture  entitled  «  Where  German  Work-People  live." 

The  photograph  of  Mendel£eff  was  supplied  by  the 
photographer,  Warwick  Brooks  of  Manchester.  The  illus- 
trations of  apparatus  used  in  cutting  and  welding  by  the 


PREFACE  ix 

oxy-acetylene  flame  were  supplied  by  Messrs.  Carbic,  Ltd. 
Messrs.  Baer  &  Co.  supplied  the  blocks  for  illustrating 
the  article  on  metallic  fire-lighters. 

Messrs.  Charles  GrifBn  &  Co.  kindly  gave  me  per- 
mission to  quote  certain  passages  from  Dr.  Wynter  Blyth's 
book  on  Poisons. 

Messrs.  Macmillan  &  Co.  courteously  gave  me  per- 
mission to  quote  from  Kingsley's  Scientific  Essays. 

To  all  of  these  I  wish  to  return  my  best  thanks  for 
the  assistance  rendered. 

GEOFFREY   MARTIN. 

UNIVERSITY  OF  LONDON. 


CONTENTS 


CHAP.  PAGB 

I.  THE  WONDERLAND  OF  MODERN  CHEMISTRY      .        .  i 

II.  THE   ROMANCE   OF    SOME    SIMPLE   NITROGEN   COM- 
POUNDS         24 

III.  THE  ROMANCE  OF  EXPLOSIVES 51 

IV.  RADIUM  AND  THE  NEW  CHEMISTRY  ....  88 
V.  THE  MYSTERY  OF  THE  PERIODIC  LAW      .         .        .112 

VI.  THE  RADIO-ELEMENTS  AND  THE  PERIODIC  LAW        .  135 

VII.  MODERN  ALCHEMY 150 

VIII.  APPLICATIONS  OF  ELECTRICITY  TO  CHEMISTRY  .         -157 

IX.  THE  ROMANCE  OF  THE  HYDROCARBONS     .        .         .  175 

X.  THE  ROMANCE  OF  SUGAR 225 

XI.  THE  ROMANCE  OF  ALCOHOL      .         .              -  .        .  242 

XII.  THE  ROMANCE  OF  COAL-TAR    .                          .        .  262 

XIII.  THE  ROMANCE  OF  COMMON  SALT      ....  291 

XIV.  METALLIC  FIRESTONES 328 

XV.  ARTIFICIAL  PRECIOUS  STONES 336 

INDEX         ........         .  349 


LIST   OF   ILLUSTRATIONS 

PLATES 
KAITEUR  FALLS         ......  Frontispiece 

PLATE  FACING   PAGE 

1.  MANUFACTURE  OF  NITRO-GLYCERINE          ...       60 

2.  INTERIOR    OF    THE    WASHING    HOUSE    OF   A    NITRO- 

GLYCERINE PLANT      ......       60 

3.  SHAPING  CHARGES  OF  GUN-COTTON  WITH  A  BAND  SAW       72 

4.  CHISELLING   AND   TURNING   BLOCKS    OF   GUN-COTTON 

FOR  CHARGING  SHELLS 72 

5.  THE  BATTLESHIP  LIBERTE  AFTER  THE  EXPLOSION  OF 

B-POWDER -76 

6.  PORTRAIT  OF  MENDELEEFF        .         .         .         .         .114 

7.  REYNOLDS-CROOKES  DIAGRAM  OF  ATOMIC  WEIGHTS    .     130 

8.  THE  VICTORIA  FALLS        .         .         .         .         .         .162 

9.  NIAGARA  FALLS 162 

10.  WATER-POWER  HARNESSED  TO  PRODUCE  ELECTRICITY     166 

11.  ELECTRIC  FURNACES,  NIAGARA  FALLS         .         .         .166 

12.  DR.    SAND'S    APPARATUS    FOR    RAPID    ANALYSIS^    BY 

MEANS  OF  ELECTRIC  CURRENT  .         .         .         .170 

13.  AN     ANCIENT     FIRE- WORSHIPPER'S     TEMPLE     NEAR 

BALAKHANI 176 

xiri 


xiv     MODERN    CHEMISTRY    AND    ITS   WONDERS 

PLATE  FACING  PAGE 

14.  A  GLIMPSE   OF  THE  FAMOUS  RUSSIAN  OIL   CITY   OF 

BAKU 176 

15.  RUSSIAN  OIL  WELLS  AT  BALAKHANI  .         .  .  .180 

1 6.  OIL  WELLS  AT  Los  ANGELES,  CALIFORNIA  .  .     180 

17.  RUSSIAN  OIL  WELL  ON  FIRE    .         .         .  .  .     190 

1 8.  GREAT  PITCH  LAKE  AT  TRINIDAD     .         .  .194 

19.  VILLAGE  OF  LA  BREA,  TRINIDAD       .         .  .194 

20.  THE  WILL-O'-THE  WISP-  .         .         .         .  t  .198 

21.  A    FIFTY-THOUSAND    BARREL    STORAGE    TANK    FOR 

PETROLEUM  IN  COURSE  OF  CONSTRUCTION  .         .     206 

22.  DEAD  MINERS,  OVERCOME  BY  CARBON  MONOXIDE       .     206 

23.  OXY- ACETYLENE  BLOW-PIPE  FOR  PIERCING  HOLES  IN 

METAL  RAILS ..222 

24.  CUTTING    9-lNCH  THICK  ARMOUR   BY  MEANS   OF  AN 

OXY- ACETYLENE  BLOW-PIPE  FLAME    .         .         .224 

25.  THE    HOME    OF     THE    SUGAR-CANE — A     SCENE     IN 

JAMAICA ,  ,         .     226 

26.  CULTIVATION   OF   BEETS  FOR   THE  MANUFACTURE   OF 

BEET-SUGAR 236 

27.  GROUP    OF    WORKERS    ON    A     SUGAR     PLANTATION, 

GUADELOUPE      .         .         .         .  /  .         .     236 

28.  BOILING    SUGAR    FOR    MAKING    SWEETS    AT    MESSRS. 

FRY  &  SONS'  WORKS,  BRISTOL  .         .         .         .238 

29.  MALTING     FLOOR     OF     MESSRS.     GUINESS     &     Co.'s 

BREWERY  IN  DUBLIN 250 

30.  MASH  TUNS  OF  MESSRS.  GUINESS  &  Co.'s  BREWERY 

IN  DUBLIN 250 


LIST    OF    ILLUSTRATIONS  xv 

PLATE  FACING   PAGE 

31.  WHERE  GERMAN  WORK-PEOPLE  LIVE          .  .  .270 

32.  STRUCTURES  OF  CRYSTALLISED  SALT  .         .  .  .296 

33.  CRYSTAL -CAVE,  WIELICZKA  SALT  MINE      ...  .     296 

34.  BALL-ROOM  HEWN  OUT  OF  SALT         .         .  .  .296 

35.  ST.  ANTHONY'S  CHAPEL,  HEWN  OUT  OF  SALT  .  .298 

36.  A  CHAMBER  EXCAVATED  IN  SALT       .         .  .  .298 


DRAWINGS    IN    THE    TEXT 


PAGE 


1.  RAILWAY  TRUCKS  SET  ON  FIRE  BY  NITRIC  ACID        .       26 

2.  NITRIC  ACID  FROM  THE  ATMOSPHERE         .         .         .3° 

3.  SOLUBILITY  OF  AMMONIA  IN  WATER  .         .         .         .       35 

4.  PREPARING    AMMONIA    BY    HEATING    LIME    AND    AM- 

MONIUM CHLORIDE      .         .         .  .         .36 

5.  AMMONIA  AND  NITRIC  ACID      .         .         .         .         .41 

6.  DENTIST   ADMINISTERING   NITROGEN   MONOXIDE  TO  A 

PATIENT 43 

7.  THE  RADIOACTIVE  ELEMENTS     .         .         .         .         .99 

8.  CURVE  OF  ATOMIC  VOLUMES 125 

9.  SODDY'S  HELICAL  REPRESENTATION  OF  PERIODIC  LAW     133 

10.  RADIO-ELEMENTS  AND  PERIODIC  LAW         .         .         .141 

11.  MOISSAN'S  ELECTRIC  FURNACE 158 

12.  SECTION  THROUGH  DR.  SAND'S  APPARATUS  FOR  RAPID 

ELECTRO- ANALYSIS      .         .         .         .         .         .170 

13.  DR.  SAND'S  ELECTRODES  FOR  ELECTRO-ANALYSIS        .     172 

14.  EXPLOSION  OF  GAS  IN  A  WELL  AT  SURAKHANI  .         .     177 


xvi     MODERN    CHEMISTRY   AND    ITS   WONDERS 

FIG.  PAGB 

15.  OIL  BURST  AT  DROOJBA .183 

1 6.  EXPLOSION  IN  A  COAL  MINE     .         .         .         .         .203 

17.  DEATH  FROM  CARBON  MONOXIDE  POISONING      .         .208 

1 8.  THE     SNAEFELL     DISASTER — BRINGING    UP     MINERS 

OVERCOME  BY  CARBON  MONOXIDE       .         .         .215 

19.  PRINCIPLE  OF  A  SAFETY  LAMP — A   FLAME  WILL  NOT 

PASS    THROUGH    WlRE    GAUZE  .  .  .  .        2iy 

20.  DAVY'S  SAFETY  LAMP         .         .         .         .         .         .219 

21.  DEATH  OF  MANSFIELD       .         .  .         .         .265 

22.  SODIUM  BURNING  ON  WATER     .....     309 

23.  MAKING  CHLORINE  GAS  IN  THE  LABORATORY     .         -311 

24.  SUNLIGHT   DECOMPOSING   CHLORINE   WATER,    OXYGEN 

GAS  BEING  LIBERATED 317 

25.  EXPLOSION    OF    HYDROGEN    AND    CHLORINE    GAS   BY 

RAY   OF  SUNLIGHT  ENTERING  THROUGH  A  HOLE 

IN  A  SHUTTER 321 

26.  SIMPLE  GAS-LIGHTER 333 

27.  SECTION  OF  GAS-LIGHTER          .         .         .         .         •     333 

28.  CIGARETTE  LIGHTER          .         .         .         .         .         .334 

29.  APPARATUS   FOR   MAKING  ARTIFICIAL  RUBIES      .         .     343 


MODERN  CHEMISTRY  AND  ITS 
WONDERS 

CHAPTER    I 

THE    WONDERLAND    OF    MODERN    CHEMISTRY 

"  And  Nature,  that  old  nurse,  took 

The  child  upon  her  knee, 
Saying  '  Here  is  a  story  book 
Thy  father  has  written  for  thee.' 

'Come  wander  with  me,'  she  said, 

*  In  the  regions  yet  untrod, 
And  read  what  is  still  to  read  unread, 
In  the  manuscripts  of  God.' 

And  he  wandered  away  and  away, 

With  Nature,  the  dear  old  nurse, 
Who  sang  to  him  night  and  day 

The  rhymes  of  the  Universe." 

So  sang  the  immortal  Wordsworth  of  the  wonders  of 
nature.  In  the  following  pages  I  hope  to  take  the  reader 
with  me  into  part  of  the  Wonderland  of  Modern  Chemistry, 
and  to  tell  him  of  facts  as  strange  or  even  stranger  than 
any  ever  fabled  in  a  fairy  tale — with  the  advantage  of 
being  perfectly  true.  But  first  of  all  I  must  say  a  few 
words  about  what  we  mean  by  the  science  of  chemistry. 
The  reader,  with  faint  memories  of  his  schooldays  float- 
ing in  his  mind,  may  have  some  sort  of  idea  that 
chemistry  deals  with  nasty  smells,  explosions,  and  such 
like  things.  This,  however,  is  a  very  distorted  view  to 
take. 


2      MODERN    CHEMISTRY    AND    ITS    WONDERS 

More  accurately  we  may  say  that  chemistry  is  the 
science  which  deals  with  the  different  kinds  of  matter  and 
their  various  transformations  into  other  kinds  of  matter. 
Consequently  wood,  tea,  metals,  glass,  acids,  poisons, 
perfumes,  rocks,  air,  gases,  water — in  a  word,  every 
substance  that  you  can  think  of,  forms  a  proper  object 
of  study  of  the  science  of  chemistry.  The  whole  great 
universe  about  us,  from  its  uttermost  heights  to  its 
deepest  depths,  is  built  up  of  matter  of  some  kind  or 
other  ;  and  so  chemistry  must  deal  intimately  with  its 
structure.  Our  bodies,  plants,  flowers,  and  the  innumer- 
able products  of  modern  civilisation — be  it  a  railway 
train  or  a  piece  of  wall-paper,  a  palace  of  marble  or 
a  reel  of  cotton — are  all  built  up  of  matter,  and 
therefore  chemistry  as  a  science  must  underlie  all  these 
things.  Ultimately  all  other  sciences  rest  upon  chemistry 
as  a  basis,  for  all  such  sciences  finally  deal  with  matter 
in  some  form  or  other. 

This  is  what  makes  chemistry  so  interesting  as  a  study  ; 
it  is  continually  giving  us  glimpses  of  unexpected  wonders. 
Many  of  the  grandest  problems  of  the  astronomer  who 
deals  with  rushing  worlds  and  blazing  suns,  of  the 
physiologist  who  treats  of  living  matter  and  the  mysterious 
vital  processes  ceaselessly  proceeding  in  every  living 
organism  and  producing  the  most  astonishing  products 
and  effects,  of  the  physicist  who  deals  with  the  mysteries 
of  light  and  heat  and  electricity  and  the  forces  which 
drive  matter  into  motion,  are  simply  chemical  ques- 
tions ;  and  all  these  classes  of  men  have  at  some  stage 
or  other  to  fall  back  upon  the  chemist  for  the  elucida- 
tion of  their  deepest  problems.  Even  geology  is  essen- 
tially a  chemical  science  ;  for  the  wearing  down  of  rocks 
and  the  countless  changes  undergone  on  the  surface  of 
the  earth  by  the  action  of  wind  and  water,  fire  and 
acids,  are  essentially  chemical  changes  ;  indeed,  the 


WONDERLAND    OF    MODERN    CHEMISTRY     3 

whole  world  is  but  a  vast  system  in  ceaseless  and  rapid 
chemical  change. 

Since  chemistry  is  the  science  which  deals  with  the 
various  kinds  of  matter,  and  since  all  industries  use  as 
their  raw  material  matter  in  some  form  or  other,  it  is 
obvious  that  chemistry  must  be  more  closely  interwoven 
with  the  industries  of  a  country  than  almost  any  other 
science.  Indeed,  for  this  reason  it  has  been  stated  that 
national  pre-eminence  in  chemical  industry  ultimately 
means  a  national  world  supremacy. 

Chemistry  gives  us  command  of  matter,  and  therefore 
the  empire  of  the  world.  The  country  that  produces 
the  best  chemists  must,  in  the  long  run,  be  the  most 
powerful  and  wealthy.  And  why  ?  Because  it  will 
have  the  fewest  wastes  and  unutilised  forms  of  matter, 
the  most  powerful  explosives,  the  hardest  steels,  the 
best  guns,  the  mightiest  engines,  and  the  most  resistant 
armour. 

It  will  have  at  lowest  cost  the  best  manufactured 
articles ;  its  food  will  be  the  most  nourishing  and  the 
cheapest.  Its  inhabitants  will  be  the  most  healthy  and 
the  best  developed,  the  most  free  from  disease  and  vice. 
They  will  be  thrifty,  resourceful,  intelligent,  utilising  their 
country's  resources  in  the  best  possible  manner  and 
opposing  the  least  resistance  to  favourable  evolution. 

Their  country  will  be  the  least  dependent  upon  other 
lands,  the  most  prosperous  in  peace,  the  most  terrible 
in  war. 

Truly  the  education  of  the  nation  in  advanced 
chemistry  and  higher  physical  science  is  the  most  paying 
investment  that  any  country  can  make.  Indeed,  one  writer 
goes  so  far  as  to  suggest  that  competition  between  civi- 
lised nations  is  merely  a  competition  in  the  science  and 
applications  of  chemistry.  Therefore  it  is  greatly  to  be 
regretted  that  in  England  our  higher  education  and 


4     MODERN    CHEMISTRY    AND    ITS    WONDERS 

universities  are  starved — the  teachers  in  great  universities 
often  living  on  pittances  such  as  skilled  artisans  would 
refuse/  while,  still  worse,  chemical  research  is  greatly 

1  Let  me  give  some  instances  of  what  is  now  (1915)  nothing  less  than  a 
national  scandal.  You  can  purchase  the  full-time  services  of  a  doctor  of 
Science,  one  who  has  discovered  several  new  facts  and  who  has  possibly 
written  a  couple  of  books,  and  who  has,  in  a  word,  brains,  ability  and  ideas 
in  abundance,  for — I  am  ashamed  to  say  it — about  £130  a  year  !  This  is  less 
than  the  wages  paid  to  an  average  clerk  of  the  same  age  in  a  bank,  far  less 
than  that  paid  to  an  average  civil  servant,  and  even  less  than  that  paid  to  a 
good  fitter  in  an  engineering  workshop.  The  financial  position  of  the  scientific 
worker  engaged  in  research  on  the  fundamental  questions  of  science  is  pitiable  in 
the  extreme.  The  reader  will  naturally  suppose  that,  at  least,  the  "teacher- 
scientists  "  on  the  staffs  of  the  great  modern  universities  like  those  of  London, 
Birmingham,  Manchester,  Bristol,  Liverpool,  and  Wales,  that  is  to  say  the  men  who 
are  the  pick  of  those  who  pass  through  the  universities,  who  do  the  bulk  of  the 
very  advanced  teaching  work  of  these  universities — much  of  it  laborious  evening 
work — all  men  with  brilliant  degrees  (possessing  in  nearly  all  cases  the  highest 
scientific  degrees  attainable,  often  possessing  the  doctorate  of  both  an  English  and 
a  German  university),  all  engaged  in  researches  and  making  discoveries  in  science 
which  aid  the  public  in  health  and  sickness,  and  whose  steady  but  unobtrusive 
work  forms  the  basis  of  the  great  scientific  discoveries  which  from  time  to  time 
startle  the  world  and  lead  to  the  creation  of  world- wide  industries — surely  such 
men  at  least  get  a  fair  wage  for  their  work,  a  wage  as  good  as  that,  say,  of  a  clerk 
in  a  bank  or  an  employee  in  the  Post  or  Patent  Office,  or,  at  least,  as  good  as  a 
second  division  civil  service  clerk. 

Nothing  of  the  sort.  They  do  not  even  obtain  a  living  wage,  still  less  a 
pension !  I  do  not  exaggerate.  Let  me  explain.  Most  of  the  research  work 
done  in  England  is  carried  out  in  our  modern  universities  by  the  teaching  staff". 
Students  do  little  because  (as  explained  below)  our  university  regulations  are 
ingeniously  framed  so  as  to  make  it  unprofitable  for  them  to  do  it.  Now  the 
staff  of  a  modern  university  is  very  sharply  divided  into  two  classes,  viz.  pro- 
fessors and  non-professors.  All  the  latter,  some  of  them  men  of  forty,  and  more, 
are  known  as  the  "  junior  staff."  A  professorship  represents  the  greatest  pros- 
perity to  which  a  scientist  can  reasonably  hope  to  reach.  The  salary  may  be  put 
as  £600  to  £800  a  year.  Comfortable,  you  will  say.  Yes,  but  meagre  com- 
pared with  that  of  a  successful  lawyer,  surgeon,  physician,  stockbroker,  or  man 
of  business. 

But  what  of  the  junior  staff?  They  start  at,  say,  twenty-two  to  twenty-five 
years  at  anything  between  £100  and  £120  a  year.  Very,  very  rarely  do  they 
ever  get  more  than  £200  or  £250  a  year  at  forty  years  of  age.  The  bulk  can 
never  obtain  professorships,  and  the  few  that  do  ultimately  attain  to  this  highest 
honour  seldom  do  so  before  they  are  forty. 

These  men  are  sweated  at  a  salary  which  commences  at  say  £120  and  possibly 
goes  up  to  £200  by  the  time  they  are  thirty-five  or  forty.  They  work  often  from 


WONDERLAND    OF    MODERN    CHEMISTRY     5 

discouraged  by  the  regulations  of  the  chief  British 
universities,  who  have  made  it  most  unprofitable  for  an 
average  student  to  indulge  in  research  of  any  kind. 

Very    different    is    the    German    system,    where    the 
universities  turn  out,  not  mere  teachers  of  little  boys  or 

nine  in  the  morning  to  ten  at  night  at  teaching  and  researching.  After  middle 
age  (if  they  survive  !)  they  may  with  luck  expect  some  improvement.  This,  then, 
is  what  the  brilliant  university  graduate  (and  only  brilliant  men  are  taken  on) 
may  expect  if  he  takes  up  pure  science  as  a  profession  : — Five  or  six  years'  hard 
work  for  a  brilliant  degree,  fifteen  years'  apprenticeship  of  still  more  laborious  and 
difficult  work  at  an  average  salary  of  £175,  and  then,  with  luck,  but  very  doubtful, 
a  possible  £600  to  £800  a  year.  This  is  the  country's  offer  to  its  best  scientific 
brains.  Three  months'  holiday  in  the  year,  I  hear  my  readers  whisper.  Nothing 
of  the  sort.  The  young  scientist  in  these  modern  universities  has  to  spend  the 
bulk  of  his  holidays  in  the  stifling  air  of  the  laboratory  working  12,  13,  and 
14  hours  a  day  at  his  subjects — if  ever  he  is  to  attain  that  professorship  which 
looms  vaguely  in  the  remote  distance. 

"  Poverty  "  is  the  excuse  put  forward  by  the  modern  university  for  sweating 
95  per  cent,  of  their  teaching  staff  at  this  sort  of  salary.  Yet  with  incredible 
meanness  they  forbid  them  to  augment  their  salary  by  outside  work,  and  every- 
one knows  that  they  raise  and  spend  hundreds  of  thousands  of  pounds  for  pre- 
tentious buildings  (what  has  Birmingham  and  Bristol  spent  within  recent  years 
on  huge  buildings  ?),  in  spite  of  the  fact  that  the  average  chemical  or  physical 
laboratory  is  as  out  of  date  in  tiventy  years'  time  as  is  a  modern  battleship,  and 
that  all  that  is  wanted  to  carry  on  the  -work  are  a  few  corrugated-iron  sheds 
fitted  with  "working  benches  with  high-pressure  water^  gas,  and  electricity  laid 
on.  It  is  men  not  buildings  that  are  the  need.  Even  when  money  is  obtained 
ear-marked  for  salaries,  a  few  more  assistants  are  appointed  at  the  same  meagre 
wage,  the  clerks  engaged  in  purely  routine  work  in  the  office  get  a  "  rise,"  but  no 
improvement  in  the  position  of  the  junior  scientific  staff  ever  takes  place.  The 
main  problem  agitating  the  university  authorities  seems  to  be  how  to  secure  in- 
credibly highly  qualified  scientists  at  incredibly  low  salaries.  Civil  servants  are 
all  assured  of  a  living  wage  by  the  time  they  are  middle-aged  men  (say  thirty- 
five  or  forty)  and  of  a  pension  afterwards.  University  teachers,  who  should  rank 
at  least  as  high  as  junior  second-class  civil  servants,  however,  do  not  attain  even 
this  nor  do  they  get  pensions.  They  are  told  that  they  must  keep  "  moving  on  " 
and  that  their  positions  are  not  permanent.  The  theory  is  that  they  must  leave 
their  positions  and  attain  better  ones,  and  the  responsibility  of  the  university 
then  ceases— though  where  they  are  to  "move  on"  to  is  left  delightfully  uncer- 
tain. Postmen,  clerks  in  banks,  &c.,  have  not  this  nightmare  hanging  over  them 
after  years  of  hard  and  honourable  work. 

Equally  miserable  is  the  pay  of  technical  chemists.  Very  often  they  are  not 
paid  more  than  labourers,  packers,  &c. — in  spite  of  the  fact  that  a  long  and  ex- 
pensive training  is  necessary  to  attain  full  chemical  qualifications. 


6      MODERN    CHEMISTRY    AND    ITS    WONDERS 

men  crammed  with  bookwork — as  our  universities  do — 
but  practical  men,  men  trained  in  methods  of  research. 
For  the  German  university  regulations  made  it  profitable 
for  the  student  to  take  up  research  work,  and  later  these 
students  were  absorbed  into  chemical  industry.  And 
the  result  ?  Germany  turned  out  chemical  products  of 
the  annual  value  of  £750,000,000  ;  and  in  certain 
chemical  products  she  dominated  the  world's  markets. 
Meanwhile  our  universities  are  merely  multiplying  ex- 
aminations and  academic  distinctions  of  all  kinds,  increas- 
ing their  difficulty  and  putting  all  sorts  of  obstacles  in 
the  way  of  research  for  students.  And  yet  so  long 
ago  as  1877  Huxley  remarked: 

"  I  would  make  accessible  the  highest  and  most 
complete  training  the  country  could  afford.  Whatever 
that  might  cost,  depend  upon  it  the  investment  would 
be  a  good  one.  I  weigh  my  words,  when  I  say  that  if 
the  nation  could  purchase  a  potential  Watt,  or  Davy,  or 
Faraday,  at  the  cost  of  a  hundred  thousand  pounds  down, 
he  would  be  dirt  cheap  at  the  money.  It  is  a  mere 
commonplace  and  everyday  piece  of  knowledge,  that 
what  these  three  men  did  has  produced  untold  millions  of 
wealth,  in  the  narrowest  economical  sense  of  the  word." 

Our  universities,  therefore,  should  aim  at  producing 
not  men  who  know  a  lot — the  assimilators  of  other 
people's  ideas — but  research  men,  men  of  a  creative  type 
of  thought,  who  are  capable  of  inventing  and  producing 
new  things,  and  are  able  to  harness  the  forces  of  nature 
to  their  ends.  If  our  university  senates  see  a  ghost  of 
a  chance  they  promptly  invent  some  fresh  examination  for 
the  benefit  of  the  hapless  students.1  They  should  diminish 

1  In  almost  any  modern  English  university,  for  example,  before  a  student  can 
attain  its  highest  Degree  in  Science  or  Arts  he  has  to  pass  no  less  than  four  or  five 
separate  examinations,  each  of  an  increasing  stage  of  difficulty,  He  is,  therefore, 


WONDERLAND    OF    MODERN    CHEMISTRY     7 

the  number  of  examinations  and  increase  facilities  for  re- 
search— as  every  scientific  academic  teacher  who  has  had 
experience  in  teaching  young  men  and  women  knows. 
Make  it  profitable  for  your  student  to  undertake  research 
and  he  will  do  it  with  enthusiasm,  and  boldly  plunge  into 
the  unknown.  Face  him  with  a  succession  of  Chinese- 
like  examinations — as  our  universities  now  do — requir- 
ing years  of  study  to  surmount,  and  leaving  the  student 
jaded  and  tired  to  death  of  mere  bookwork  at  the  end 
of  it  all,  and  you  find  that  the  average  student  will  never 
have  the  energy  or  freshness  left  after  all  those  wasted 
years  to  face  research,  which  is  itself  hard  and  weary 
work. 

In  England  and  Scotland  our  university  research 
laboratories  are  empty,  but  our  "  knowledge-cramming  " 
classes  full.  In  Germany  the  research  laboratories  were 
full  and  the  "  cramming "  classes  empty — the  result  of 
wise  university  legislation  in  the  latter  country. 

What  has  already  been  achieved  by  chemical  research 
may  be  realised  when  I  tell  the  reader  that  within  the 
last  few  years  there  have  been  obtained  synthetic  dyes 
far  brighter  and  more  durable  than  any  natural  dyes, 
artificial  fibres  far  more  lustrous  than  any  natural  fibres, 
manufactured  scents  a  thousand  times  more  powerful 
than  any  natural  scents,  wonderful  new  artificial  drugs 
which  have  revolutionised  dentistry  and  medicine,  abolished 
pain  and  disease,  and  which  allow  the  most  astonishing 
surgical  operations  to  be  performed  without  pain  or 
danger.  I  might  also  mention  artificial  substitutes  for 
bone  and  ivory,  horn  and  leather,  rubber  and  resins 

during  the  whole  of  his  four  or  five  years  of  student  life  kept  in  a  turmoil  of  examina- 
tions, and  the  only  knowledge  which  appeals  to  him  is  that  which  will  help  him 
to  answer  a  probable  examination  question.  The  effect  of  this  mental  attitude  on 
the  teacher  may  be  easily  imagined.  He  dares  not  touch  on  anything  except 
those  portions  of  science  which  adapt  themselves  to  examination  requirements — 
otherwise  he  loses  the  interest  of  his  hearers  ! 


8      MODERN    CHEMISTRY    AND    ITS    WONDERS 

(often  superior  to  the  natural  articles  as  regards  some 
properties),  and  tough  transparent  substances  like  celluloid 
and  other  film-making  materials,  which  have  allowed  the 
wonderful  development  of  living  pictures  and  motion 
photography.  Perhaps,  however,  the  greatest  achieve- 
ment of  modern  chemists  is  the  discovery  of  explosives 
of  terrific  power,  which  have  enabled  man  to  blast  his 
way  through  mountain  and  valley,  and  have  rendered 
possible  those  truly  astonishing  modern  engineering 
feats  which  are  rapidly  transforming  the  whole  surface  of 
our  planet. 

When  I  tell  the  reader  that  all  these  things  are  but 
the  prelude  to  far  greater  achievements,  which  will 
ultimately  lead  to  the  harnessing  of  the  natural  forces 
of  the  Universe  by  man,  he  will  realise  that  chemical 
research  is  no  dry  and  uninteresting  subject,  but  is  one 
which  teems  with  problems,  the  solution  of  which  will 
bring  into  the  grasp  of  the  solver  prizes  of  immense 
value. 

At  one  time — and  that  quite  recently  too — terrible 
epidemics  swept  across  the  world,  decimating  the  human 
race. 

The  great  plague,  for  example,  coming  from  China 
swept  right  across  Russia  and  Europe  into  England. 
We  are  told  that  grass  grew  in  the  streets  of  London 
and  the  dead  were  so  numerous  that  there  were  scarcely 
enough  men  left  to  bury  them !  This  was  simply  an 
invasion  of  foreign  bacteria,  far  more  deadly  than  any 
invasion  of  human  foes  ;  even  at  the  present  time  such 
invasions,  causing  bacterial  diseases,  levy  a  frightful  toll 
upon  the  human  race,  killing  annually  millions  of 
men,  women,  and  children.  By  the  manufacture  of 
bacterial  killing  substances — the  so-called  "  antiseptics  " — 
the  chemist  has  done  much  to  save  us  from  disease  ; 
it  is  safe  to  state  that  now  it  would  be  impossible  for 


WONDERLAND    OF    MODERN    CHEMISTRY     9 

plague  to  sweep  over  the  world  and  decimate  the  whole 
human  race,  as  it  formerly  did,  not  once,  but  many  times. 
Antiseptics  have  obviated  for  ever  such  a  possibility,  and 
the  world  has  to  thank  chemists  for  this  great  advance. 
At  the  present  time  chemical  remedies  are  known  for 
many  diseases,  and  many  authorities  believe  that  a  time 
will  come  when  diseases  like  typhoid  and  scarlet  fever 
will  be  as  rare  as  are  now  fatal  mechanical  accidents 
among  civilised  races.  Indeed,  many  diseases,  at  one  time 
regarded  as  very  dangerous,  are  now  considered  scarcely 
worse  than  an  ordinary  cold. 

The  chemist  also  protects  usfrom professional  poisoners, 
who  once  flourished  in  Europe  to  an  almost  incredible 
extent,  and  who  still  flourish  to  some  extent  in  many 
Eastern  countries.  In  past  times  almost  every  man  of 
note  went  in  danger  of  secret  poisoners,  and  medical 
science  was  then  not  sufficiently  advanced  to  decide 
whether  a  man  died  suddenly  in  a  fit  or  from  a  swift 
poison.  Now,  however,  all  this  is  changed,  for  by  the 
swift  and  sure  means  of  chemical  analysis  the  chemist 
can  detect  poisons  in  the  human  body  even  after  the  un- 
fortunate victim  has  been  dead  for  months,  and  so  can 
bring  the  guilty  ones  to  justice.  Secret  poisoning,  thanks 
to  chemists,  is  now  almost  as  deadly  to  the  poisoner 
himself  as  to  the  victim  ! 

Chemistry  has  revolutionised  not  only  the  Arts  of 
Peace  but  also  the  Art  of  War.  Whence,  for  example, 
has  come  the  knowledge  that  has  made  possible  the  long, 
slow  evolution  of  the  rude  bow  and  arrow  of  the  savage 
into  the  great  guns  of  to-day  ?  Surely  from  the  laboratory 
of  the  chemist.  He  has  given  us  our  fine  steels  and  our 
high  explosives  without  which  modern  armament  would 
be  impossible.  The  modern  battleship  is  but  a  vast  float- 
ing engineering  shop,  whose  death-dealing  appliances  derive 
their  irresistible  power  from  explosive  chemicals.  Like- 


io     MODERN    CHEMISTRY  AND   ITS   WONDERS 

wise  the  airship,  the  aeroplane,  the  waterplane — where 
were  they  invented  ?  Not  on  the  battlefield,  but  in  the 
shed  of  the  scientific  inventor ;  not  until  the  chemist  had 
discovered  how  to  distil  out  volatile,  explosive  components 
from  oil,  wherewith  to  furnish  the  motive  power  for  their 
engines,  was  their  advent  possible. 

All  these  are  practical  achievements  the  value  of  which 
can  be  realised  by  the  average  man  in  the  street.  But 
chemists  have  made  discoveries  which  lead  us  right  into 
a  fairy  land  of  science,  discoveries  which  must  appeal  to 
the  imagination  of  every  thoughtful  person,  and  which 
enable  us  to  withdraw  awhile  from  the  cares  of  life  and 
enjoy  the  calm  of  science : — 

"  The  silence  that  is  in  the  starry  sky, 
The  sleep  that  is  among  the  lonely  hills." 

We  all  know  that  the  astronomer  deals  with  things  of 
infinite  vastness,  the  grandeur  of  which,  the  revealing  of 
series  of  worlds  stretching  away  in  endless  vistas  into 
space,  strike  with  awe  even  the  most  thoughtless  mind. 
The  chemist  has  revealed  equally  wonderful  things  in  the 
domain  of  the  infinitely  small ;  he  has  directed  the  arm 
of  reason  into  regions  of  almost  inconceivable  minuteness 
to  weigh  and  measure  the  tiny  atoms  which  build  up 
matter — objects  so  small  that  they  lie  as  far  beyond  the 
vision  of  the  most  powerful  microscopes  as  these  carry 
their  vision  beyond  that  of  the  naked  eye.  Nay,  recently 
the  chemist  has  passed  beyond  the  atom  itself  and  has 
revealed  to  our  astonished  gaze  a  domain  in  which  the 
atoms  themselves  loom  as  great  galaxies  built  up  of  still 
tinier  particles.  And  thus  the  chemist  has  given  us  a 
truly  astonishing  vision  of  universe  within  universe  reced- 
ing into  the  infinitely  small — just  as  the  astronomer  has 
revealed  to  us  universe  within  universe  stretching  away  into 
the  infinitely  great.  The  whole  vista  thus  opened  out  by 


WONDERLAND    OF    MODERN    CHEMISTRY     n 

modern  chemistry  lays  bare  hitherto  unsuspected  depths  of 
complexity  in  the  commonest  and  most  insignificant  things 
about  us.  Tennyson  long  ago  expressed  this  grand  truth 
in  the  lines  : — 

"  For  Knowledge  is  the  Swallow  on  the  lake 
That  sees  and  stirs  the  surface-shadow  there 
But  never  yet  hath  dipt  into  the  abysm, 
The  abysm,  of  all  abysms,  beneath,  within, 
The  blue  of  the  sky  and  sea,  the  green  of  Earth 
And  in  the  million-millionth  of  a  grain 
Which  cleft  again  for  evermore, 
And  ever  vanishing,  never  vanishes, 
To  me,  my  son,  more  mystic  than  myself 
Or  even  than  the  nameless  is  to  me." 

And  now  what  of  the  men  who  have  achieved  these 
wonders — the  workers  in  the  rank  and  file  of  the  great 
scientific  army  ?  What  manner  of  men  are  they  ?  Well 
it  must  be  confessed  that  the  majority  are  very  ordinary 
individuals,  certainly  not  even  approximately  as  dis- 
tinguished looking  as  poets  or  artists  or  actors  or  soldiers. 
They  wear  neither  long  hair  nor  exaggerated  neckties, 
nor  have  their  clothes  an  extraordinary  cut.  Indeed, 
beyond  the  fact  that  they  are  somewhat  more  shabby 
than  the  ordinary  business  man  there  is  nothing  to  dis- 
tinguish the  average  scientist  from  the  average  man  in 
the  street.  The  popular  notion  that  Science  is  a  happy 
family  of  mutually  admiring  absent-minded  philanthropists, 
each  striving  for  the  benefit  of  the  human  race,  is  very 
far  from  being  a  picture  of  the  reality.  So  far  from 
thinking  solely  of  benefiting  the  human  race,  most  pro- 
fessional scientists,  I  am  afraid,  are  much  more  concerned 
about  earning  enough  money  to  buy  their  wives  nice  hats 
and  bring  up  their  families  respectably  !  In  fact,  they 
are  just  ordinary,  everyday  men.  The  scientific  world 
is  a  very  restricted  one  with  prizes  few  and  far  be- 


12     MODERN   CHEMISTRY  AND    ITS  WONDERS 

tween,  where  the  struggle  for  survival  is  as  fierce  as  in 
any  natural  species,  and  where  bitterness  and  spite  and 
disappointed  hopes  are  as  prevalent  as  in  the  industrial 
or  artistic  world.  As  in  other  branches  of  activity,  the 
"  top  "  is  no  limitless  plateau  with  room  for  all  scientists. 
Rather  it  is  a  spiky  pinnacle  whereon  a  few  eminent 
professors  uncomfortably  sit,  and  occupy  most  of  their 
spare  time  in  shoving  down  their  junior  colleagues  who 
would  presume  to  climb  to  the  same  level. 

More  often  than  not  great  scientists  pass  their  lives  in 
obscurity.  Yet  they  have  this  consolation — their  achieve- 
ments will  ultimately  be  recognised  and  will  spur  unborn 
generations  on  to  fresh  endeavours : — 

"  He  is  not  dead  whose  glorious  mind 

Lifts  thine  on  high. 
To  live  in  hearts  we  leave  behind, 
Is  not  to  die." 

How  often  do  we,  when  engaged  in  investigating  new 
and  unknown  regions  of  science,  come  across  the  work 
of  men  dead  and  forgotten  scores  of  years  ago  ;  their 
personality  again  lives  before  us  in  their  writings,  and 
we  idly  wonder  concerning  their  forgotten  struggles  and 
difficulties.  There  is  one  thing  every  scientific  investigator 
must  bear  in  mind — and  that  is  accuracy.  Facts  which 
are  inaccurate  and  which  live  in  the  literature  of  science 
for  a  time,  ultimately  come  home  to  roost — a  Nemesis  to 
the  hasty  and  inaccurate  worker.  As  Goethe  put  it : — 

"  Haste  not,  let  no  thoughtless  deed 
Mar  for  aye  the  spirit's  speed. 
Ponder  well,  and  know  the  right, 
Onward  then,  and  know  thy  might ; 
Haste  not,  years  can  ne'er  atone 
For  one  reckless  action  done." 

As   a  class,  successful  scientists   have  one  or  two  small 


WONDERLAND    OF    MODERN    CHEMISTRY      13 

characteristics   which  differentiate  them  somewhat  from 
other  classes  of  men. 

In  the  first  place,  a  scientific  discoverer  owes  his  success 
to  a  highly  developed  but  peculiar  mental  characteristic — 
and  that  is  excessive  attention  to  minute  detail.  His  is 
a  mind  which  frets  itself  into  a  frenzy  about  minute  dis- 
crepancies which  an  ordinary  individual  would  regard 
as  too  minor  for  serious  attention.  Nearly  all  great 
discoveries  have  been  made  by  this  attention  to  little 
discrepancies. 

"  Powers   of  careful  observation "  is  the  euphemistic 
term  by  which  scientists  denote  this  necessary  character- 
istic for  discovery.     Consequently  your  successful  scientist 
tends   to  attach  exaggerated  importance  to    little  things. 
He   is    a    "crochety,"    "finicking"   individual.      This    is 
why    scientists    are   always    quarrelling,   disputing  about 
petty  details.    They  are  remarkably  jealous  of  each  other, 
usually  referring  to  work  other  than  their  own  as  "  very 
ordinary "    if  it  is    a  careful,   exact    piece    of    research  ; 
whereas  it  becomes  "  too  speculative  "  if  the  worker  goes 
in  for  any  degree   of  originality,  and  the  poor  man    is 
always  spoken  of  (behind  his  back)  as  "  quite  unsound." 
Most  eminent  scientists   in  any  one   branch   are   deadly 
enemies.      Indeed,  it  is  a  most  entertaining — -if  not  a  dig- 
nified— spectacle,  to  see  one  eminent  professor  "  slating  " 
another  eminent  professor's  book  in  hypercritical  reviews. 
Moreover,  those  professors  who  write  books  look  down 
on  those  who  merely  do  research  work,  and  vice  versa. 
Their  ideas  are  usually  distorted  as  regards  the  relative 
value  of  things,  and  it  is  this  which  has  led  to  the  current 
English  notion  that  a  scientist  is    "  unpractical "   and   a 
"  Fuss  pot."     I  doubt  whether  scientists  could  govern  a 
state  any  more  than  artists  or  actors  could.      Scientists 
deal  with  Nature,  but  Statesmen  deal  with  men,  and  the 
qualities   which   tend   for   success   in  the  one  branch  of 


14     MODERN   CHEMISTRY  AND    ITS  WONDERS 

activity  will  often  be  the  antithesis  of  the  qualities  needed 
for  success  in  the  other  sphere  of  activity. 

The  average  English  business  man — whose  success  in 
life  depends  entirely  upon  exercising  commonsense — 
when  brought  into  contact  with  the  new,  strange  world 
in  which  the  scientists  wander,  views  with  blank  aston- 
ishment these  men  disputing,  quarrelling,  and  attacking 
each  other  about  what  seem  to  him  the  veriest  trifles  ; 
he  classifies  the  whole  pack  as  a  lot  of  semi-maniacs. 
This  attitude  of  mind  is  largely  responsible  for  the  utter 
lack  of  sympathy  which  prevails  in  England  between 
scientists  and  the  business  world,  and  is  the  real  reason 
why  scientists  as  a  class  are  so  miserably  poor. 

"The  beakers  and  flasks  of  the  scientific  investigator," 
said  the  great  German  chemist,  Emil  Fischer,  "  are  minute 
compared  with  the  vats  employed  by  the  chemical  manu- 
facturer. This  relative  difference  in  size  also  corresponds 
to  the  comparative  wealth  of  these  two  classes  of  men." 

Certainly  if  scientists  as  a  class  had  any  business  ability 
they  would  have  long  ago  improved  the  pittances  which  are 
now  paid  to  fully  trained  men.  Scientists  simply  do  not 
realise  their  power,  and  fail  entirely  to  act  in  a  united 
manner  to  secure  proper  recognition  of  their  services. 
They  should  be  protected  from  exploitation,  especially 
as  the  average  Englishman  thinks  that  it  is  the  duty  of 
every  scientist  to  be  a  "  martyr  to  science." 

These  peculiarities  of  scientists  have  been  noted  for 
centuries.  Thus  in  the  old  work  entitled  Physica  Sub- 
tenanaea,  published  nearly  two  hundred  years  ago,  we 
read  the  following : — 

"  The  chymists  are  a  strange  class  of  mortals  impelled 
by  an  almost  insane  impulse  to  seek  their  pleasures  among 
smoke  and  vapour,  soot  and  flame,  poisons  and  poverty, 
yet  among  all  these  evils  I  seem  to  live  so  sweetly,  that 


WONDERLAND    OF    MODERN    CHEMISTRY      15 

may   I   die    if  I   would    change  places  with  the  Persian 
King." 

Charles  Kingsley,  who  undoubtedly  would  have  made 
a  great  scientist  if  his  walk  in  life  had  lain  in  another 
sphere,  speaks  some  admirable  words  on  the  disinterested 
labours  of  scientists.  They  are  well  worth  quoting, 
although  I  am  afraid  they  envelop  the  scientist  with  an 
idealistic  atmosphere  which  one  better  acquainted  with 
this  species  of  the  human  race  would  know  is  far  removed 
from  the  reality. 

In  a  lecture l  delivered  to  the  Royal  Institution  many 
years  ago,  he  said,  speaking  of  Science  : — 

"  Her  votaries  have  not  as  yet  cared  much  for  purple 
and  fine  linen,  and  sumptuous  fare.  There  are  very  few 
among  them  who,  joining  brilliant  talents  to  solid  learning, 
have  risen  to  deserved  popularity,  to  titles  and  to  wealth. 
But  even  their  labours,  it  seems  to  me,  are  never  rewarded 
in  any  proportion  to  the  time  and  the  intellect  spent  on 
them,  nor  to  the  benefits  which  they  bring  to  mankind  ; 
while  the  great  majority,  unpaid  and  unknown,  toil  on 
and  have  to  find  science  her  own  reward.  .  .  .  They 
are  engaged  in  a  war — a  veritable  war — against  the  rulers 
of  darkness,  against  ignorance  and  its  twin  children,  fear 
and  cruelty. 

"  I  can  conceive  few  human  states  more  enviable  than 
that  of  the  man  to  whom,  panting  in  the  foul  labora- 
tory, .  .  .  Isis  shall  for  a  moment  lift  her  sacred  veil, 
and  show  him,  once  and  for  ever,  the  thing  he  dreamed 
not  of ;  some  law,  or  even  mere  hint  of  a  law,  connecting 
them  all  with  each  other  and  with  the  mightier  whole, 
till  order  and  meaning  shoots  through  some  chaos  of 
scattered  observations.  Is  not  that  a  joy,  a  prize,  which 
wealth  cannot  give  nor  poverty  take  away  ?  " 

1  Kingsley,  Scientific  Essays,  published  by  Macmillan  &  Co. 


16     MODERN   CHEMISTRY  AND   ITS   WONDERS 

Kingsley  elsewhere  observes  of  the  scientist : — 

"He  is  following  a  mistress  who  has  never  yet  con- 
ferred aught  but  benefits  on  the  human  race." 

And,  yet,  to  this  very  day,  the  scientist  in  the  stage  play 
or  average  novel  is  always  represented  as  a  villain,  seek- 
ing to  murder  someone  by  the  aid  of  mysterious  powers ! 
Tennyson,  who  had  possibly  an  intimate  personal 
knowledge  of  scientists,  had  a  decidely  lower  opinion  of 
them  than  Kingsley.  Tennyson  naturally  thought,  that 
men  who  dealt  with  the  mysteries  of  the  universe  ought 
to  possess  lofty  and  poetic  minds.  He  found  them,  how- 
ever, like  ordinary  mortals,  concerned  with  petty  things 
and  petty  spites,  and  so  in  "  Maud  "  he  described  them  as 
having : — 

"  An  eye  well-practised  in  Nature,  a  spirit  bounded 
and  poor." 

However  this  may  be,  I  do  not  think  that  anyone 
can  deny  the  really  astonishing  achievements  of  modern 
chemists,  or  dispute  the  truth  of  Kingsley's  words : — 

"  What  physical  science  may  do  hereafter  I  know  not ; 
but  as  yet  she  has  done  this :  She  has  enormously  in- 
creased the  wealth  of  the  human  race ;  and  has  therefore 
given  employment,  food,  existence,  to  millions  who,  with- 
out science,  would  either  have  starved  or  have  never  been 
born." 

It  is  not  the  fault  of  science  that  Germany  has 
harnessed  her  to  the  chariot  of  death  and  destruction. 
Science  is  potent  beyond  all  belief  for  good — but  she 
puts  terrible  powers  into  the  hands  of  madmen. 

Chemists  have  even  dared  to  leave  the  inanimate 
world  and  have  attacked  the  problem  of  life  itself. 
In  earlier  times,  even  so  recently  as  the  first  de- 
cades of  the  nineteenth  century,  men  looked  with  awe 


WONDERLAND    OF    MODERN    CHEMISTRY     17 

upon  the  mysterious  region  of  vital  chemistry.  They 
saw  plants  and  animals  produce  with  ease  and  in  abun- 
dance innumerable  curious  substances  which,  in  the 
laboratory,  men  failed  altogether  to  produce  ;  to  mention 
a  few :  beautiful  dyes,  which  tinge  plants  and  animals 
the  most  exquisite  colours,  from  the  soft  pink  of  the 
rose,  through  shades  of  glorious  red  of  the  carnation, 
to  wonderful  tints  of  yellow,  green,  and  purple  ;  sweet 
tasting  sugars,  beautiful  perfumes,  powerful  poisons,  and 
wonderful  healing  drugs,  all  produced  by  the  strange 
chemistry  of  plant  and  animal  life.  Yet  up  to  the  year 
1827  no  man  had  ever  produced  in  the  laboratory  a 
single  one  of  these  bodies,  and  chemists  hovered  awe- 
stricken  at  the  entrance  of  this  vast  chemical  domain,  fearing 
to  enter,  and  regarding  all  these  products  of  the  wonder- 
ful life-activity  of  animal  and  vegetable  life  as  the  direct 
manifestation  of  mysterious  vital  forces  which  prevailed 
only  in  living  matter  and  which  produced  results  which 
no  man  could  imitate.  Indeed,  not  a  few  persons  were 
of  the  opinion  that  even  to  dare  to  enter  this  region,  and 
to  endeavour  to  understand  the  processes  by  means  of 
which  animals  and  plants  produced  these  astonishing 
results,  was  something  in  the  nature  of  blasphemy,  being 
in  their  opinion  attempts  to  spy  upon  the  secrets  of  the 
living  God  and  to  observe  how  he  brought  forth  in  secret 
the  wonders  of  the  living  world. 

And  so  it  came  about  that  the  whole  scientific  world 
was  in  1827  thrilled  by  the  announcement  that  a  scientist 
had  actually  made  a  substance  artificially  which  until  that 
time  had  been  brought  forth  solely  in  the  laboratories  of 
the  animal  body.  For  in  that  year  the  great  German  chemist 
Wohler  succeeded  in  making  in  an  artificial  manner  from 
purely  mineral  substances  the  white  crystalline  substance 
called  urea — a  typical  vital  product.  We  can  well 
imagine  the  wonder  and  delight  with  which  Wohler  first 

B 


i8     MODERN   CHEMISTRY  AND    ITS  WONDERS 

gazed  upon  artificial  urea — a  substance  now  manufactured 
artificially  in  tons  at  a  time — and  solemn  must  have  been 
the  thought  which  flashed  through  his  mind  that  now  for 
the  first  time  in  all  the  ages  since  the  world  began,  he 
gazed  upon  an  artificial  organic  product. 

This  feat  was  the  forerunner  of  many  other  similar 
ones.  Fats  were  made  artificially  so  far  back  as  two 
generations  ago  by  Berthelot  of  Paris. 

Artificial  grape  sugar  saw  the  light  twenty  years  ago 
at  Wiirzburg.  Artificial  dyes  innumerable  are  now  manu- 
factured in  tons  at  a  time,  and  to-day  great  industries  have 
arisen  in  which  millions  of  pounds'  worth  of  substances, 
formerly  only  known  as  the  product  of  vital  activity,  are 
annually  produced  by  purely  chemical  means.  It  is 
therefore  altogether  hard  to  realise  the  time  when  the 
production  of  a  single  artificial  organic  substance  was  the 
cause  of  endless  astonishment. 

Now  such  products  are  so  common  that  men  have 
ceased  to  take  any  notice  of  them.  It  is  true  that  only 
comparatively  simple  organic  bodies  have  been  thus 
obtained  in  the  laboratory.  The  immensely  more  com- 
plex organic  substances,  such  as  albumen,  have  not  yet 
been  synthesised  ;  but  yet  recently  a  beginning  has  been 
made.  Thus  within  the  last  dozen  years  Emil  Fischer 
in  Berlin  has  worked  out  methods  for  the  artificial 
building  up  of  albuminous  substances,  and  in  1911  showed 
a  small  bottle  full  of  the  substance  thus  obtained.  This 
synthetic  protein,  however,  is  anything  but  cheap.  The 
starting  materials  for  its  preparation  cost  about  £50, 
and  the  labour  involved  in  its  preparation  must  have 
been  much  more  costly  than  even  this,  and  so  the 
substance  has  not  as  yet  appeared  on  the  breakfast  table 
as  a  food  !  It  was  exhibited  simply  as  a  chemical  curiosity. 
But  one  must  remember  that  the  chemical  curiosities 
of  to-day  are  to-morrow  world-wide  articles  of  commerce, 


WONDERLAND   OF    MODERN    CHEMISTRY      19 

and  so  this  synthetic  protein  may  be  the  forerunner  of 
a  world-industry  of  artificial  foodstuffs. 

The  reader  must  recollect,  too,  that  at  the  present 
time  the  whole  human  race  has  to  rely  for  food  and 
warmth  upon  grains,  roots,  fruits  and  fibres,  and  upon 
animals  to  whom  organic  nutriment  is  as  essential  as  it 
is  to  us.  It  is  true  that  Science  can  do  much  by 
intensive  cultivation  and  by  scientific  feeding  to  increase 
our  planet's  stock  of  foodstuffs.  But  there  is  an  ultimate 
limit  to  the  productive  powers  of  the  soil  of  our  planet, 
and  although  we  may  increase  it  greatly  by  scientific 
means,  yet  the  population  will  increase  in  equal  ratio 
and  no  doubt  will  go  on  increasing  long  after  the 
reproductive  power  of  the  soil  has  reached  its  limit. 

But  what  a  new  vista  would  open  out  if  Science 
should  discover  some  means  of  enabling  us  to  feed  on 
inorganic  material  such  as  surrounds  us  on  every  side 
in  untold  billions  of  tons  1  The  atmospheric  nitrogen, 
which  is  about  us  on  every  side  and  of  which  some 
seven  tons'  weight  rests  on  every  square  yard  of  the 
world's  surface — sufficient  nitrogen  for  nearly  fifty  tons 
of  living  matter — is  even  now  being  fixed  by  electrical 
means  and  converted  into  manures,  and  so  ultimately* 
into  food.  But  Emil  Fischer's  synthesis  of  simple  proteins 
is  a  stage  further  than  this.  It  represents  the  artificial 
production  of  actual  foodstuffs  by  purely  chemical  means, 
from  the  purely  inorganic  materials  which  surround  us 
on  every  side  in  millions  of  tons.  And  if  Science  should 
so  advance  as  to  make  the  production  of  this  artificial 
food  an  easy  matter — giving  us  bread,  so  to  speak,  from 
the  air  and  stones  about  us — then  food  would  become  so 
inexpensive  and  so  abundant  that  the  human  race  could 
multiply  into  numbers  which  altogether  baffle  conception. 

The  difficulties  to  be  surmounted,  however,  are  stu- 
pendous. Nevertheless  the  very  bread  we  eat,  and  most 


20     MODERN   CHEMISTRY  AND   ITS  WONDERS 

of  our  foodstuffs,  may  yet  be  produced  on  a  manu- 
facturing scale  by  chemical  means.  Then,  indeed,  a  new 
epoch  will  have  dawned  for  the  whole  human  race. 
Mankind  will  have  reached  a  new  stage  in  his  upward 
development.  And  what  the  end  of  it  all  will  be  we 
cannot  even  guess.  It  may  be  that  we  are  just  in  the 
beginning  of  the  beginning,  as  Tennyson  hinted  in  the 
pregnant  words : — 

"Well — were  it  not  a  pleasant  thing 
To  fall  asleep  with  all  one's  friends 
And  every  hundred  years  to  rise 
And  leave  the  world,  and  sleep  again  : 
To  sleep  thro'  terms  of  mighty  wars, 
And  wake  on  Science  grown  to  more, 
On  secrets  of  the  brain,  the  stars, 
As  wild  as  aught  in  fairy  lore ; 
Titanic  forces  taking  birth 
In  divers  seasons,  divers  climes, 
For  we  are  the  Ancients  of  the  Earth 
And  in  the  morning  of  the  times." 

On  the  other  hand,  it  may  be  that  Science  will  not 
continue  to  advance  at  her  present  swift  rate  of  progress.1 

1  One  great  danger  to  the  ultimate  progress  of  Science  is  the  rise  into  power 
of  the  great  Scientific  Societies,  whereby  the  whole  of  crystallised  scientific  thought 
becomes  vested  in  the  hands  of  a  few  men,  who,  like  the  Theological  Societies 
of  old,  will  crush  and  suppress  any  attempt  of  scientists  to  break  away  from 
established  tenets  or  establish  free  modes  of  thought  among  themselves. 

Paradoxical  though  it  may  seem,  a  period  of  reaction  follows  the  work  of 
every  great  original  thinker,  and  the  mistakes  or  influence  of  a  Newton  or  a 
Helmholtz  often  paralyse  for  many  years  the  labours  of  workers  in  whole  branches 
of  thought  which  were  traversed  by  these  great  minds.  A  great  thinker  like 
Aristotle  probably  put  back  scientific  thought  for  2000  years  !  Now  when 
immensely  rich  and  immensely  powerful  International  Scientific  Societies  (Science 
is  International)  adopt  as  fairly  and  irrevocably  established  certain  great  theories 
and  methods  of  investigation,  their  power  to  crush  free  thought  and  free  investiga- 
tion is  enormous,  and  their  motives  in  doing  it  will  be  identical  with  the  motives 
which  impelled  the  Priesthood  to  crush  free-thinkers  in  the  Middle  Ages — namely 
the  firm  conviction  that  in  so  doing  they  are  benefiting  the  human  race  and 
doing  the  right  thing.  The  reader  must  remember  that  human  nature  is  un- 


WONDERLAND    OF    MODERN    CHEMISTRY     21 

It  may  be  that  a  long  period  of  stagnation,  lasting  for 
thousands  of  years,  may  follow  the  present  epoch  of 
enhanced  activity.  But  of  this  period  of  stagnation  we  can 
at  present  detect  no  sign.  Science,  aided  by  thousands  of 
busy  brains,  is  striding  onwards  so  swiftly  that  no  single 
man  can  keep  pace  with  her  or  prophesy  into  what  unknown 
regions  of  fact  and  thought  she  will  next  launch  us. 

As  yet  we  are  far  from  any  information  which  will 
lead  us  to  expect  the  artificial  making  of  any  piece  of 
living  matter  in  our  laboratories.  The  simplest  organism 
is  marvellously  complex,  the  end  product  of  billions  of 
years  of  evolution  in  Nature's  laboratory. 

However  "biological  chemistry" — as  the  science  which 
deals  with  vital  processes  is  called — is  already  well-estab- 
lished and  rapidly  advancing.  Its  progress  is  fraught  with 
the  most  momentous  consequences  to  the  human  race. 

In  biological  chemistry  most  processes  are  carried  on 
by  means  of  mysterious  substances  called  "  enzymes " 
which  up  to  this  time  have  never  been  obtained  in  a  pure 
condition,  but  which  cause  chemical  changes  to  take 
place  without  themselves  undergoing  much  change.  Now 
since  we  are  dependent,  not  only  for  the  assimilation 
of  our  very  food,  but  also  for  a  large  part  of  '  our 
luxuries  and  comforts,  upon  these  changes,  it  will  readily 
be  seen  that  when  man  acquires  the  power  of  guiding 
them  very  strange  things  may  come  to  pass.  Most  of 

changed,  and  that  the  irresistible  tendency  of  all  men  is  to  resent  any 
attempt  to  deviate  from  the  established  order  of  things.  Science  can  only 
advance  by  allowing  freedom  of  thought,  and  even  when  men  hold  opinions 
which  we  feel  absolutely  certain  are  incorrect,  tolerance  should  be  extended  to 
such  views.  Advances  are  always  made  by  minorities,  whose  opinions,  gradually 
gaining  ground,  finally  become  majorities^  only  in  turn  to  be  assailed  by  other 
minorities.  The  power  of  the  few  men  who  control  the  English  and  the  German 
Chemical  Societies  is,  at  the  present  time,  simply  enormous.  They  completely 
sway  between  them  the  whole  of  scientific  chemical  activity  in  this  country  and 
abroad.  Should  such  men  become  too  conservative  they  could  block  and  sup- 
press original  ideas  and  make  chemistry  a  stagnant  science.  See,  for  example, 
p.  119. 


22     MODERN   CHEMISTRY   AND   ITS  WONDERS 

the  countless  chemical  changes  which  occur  in  the  animal 
and  vegetable  kingdoms — some  of  them  of  a  truly  wonder- 
ful nature — are  due  to  the  action  of  these  enzymes.  Many 
of  the  oldest  industries  of  the  world's  history — the  making 
of  wine,  beer,  and  vinegar,  the  souring  and  clotting  of 
milk  to  form  cheese,  the  tanning  of  hides — are  dependent 
upon  the  formation  of  enzymes  in  the  bodies  of  bacteria 
or  in  living  tissues.  The  same  is  true  of  the  fermentation 
processes  employed  in  the  retting  of  flax,  in  the  curing 
of  tea  and  tobacco,  coffee  and  cocoa.  Even  the  coagula- 
tion of  blood  from  a  wound  (which  stops  bleeding)  and 
the  processes  of  digestion  are  all  dependent  upon  enzymes. 
So  also  are  modern  processes  for  disposing  of  sewage  by 
bacterial  oxidation.  Now  that  these  results  of  biological 
science  are  being  applied  in  the  service  of  industrial  and 
economic  chemistry,  the  results  which  will  ultimately 
follow  are  altogether  difficult  to  foresee. 

The  influence  of  these  discoveries  on  our  ideas  of 
the  mechanism  of  life  itself  is  very  great.  Although  the 
fundamental  secret  of  the  nature  of  life  still  remains, 
and  will  long  remain,  hidden  from  our  eyes,  yet  it  is 
indisputable  that  much  which  was  quite  recently  regarded 
as  vital  and  inseparable  from  living  matter  has  been 
proved  to  depend  upon  conditions  which  can  be  realised 
'apart  from  the  living  organism  ;  it  is  indisputable 
that  the  veil  hiding  the  actual  crude  material  mechanism 
by  means  of  which  the  vital  processes  are  carried  on, 
is  being  rapidly  drawn  aside  by  the  chemist.  But 
unfortunately  this  brings  us  little  nearer  to  the  mystery 
of  life  itself.  For  example,  what  is  Thought  and  all  the 
allied  mental  phenomena  ?  How  can  any  rolling  con- 
course of  atoms  thrill  thought  and  consciousness  into 
matter  ?  It  avails  not  how  complex  a  system  we  conceive 
of  flashing  atoms  and  sub-atoms,  for  our  chemistry 
cannot  explain  how  thought  arises  from  their  motions 


WONDERLAND   OF    MODERN    CHEMISTRY     23 

and  arrangements.  It  may  be  true  that  the  notion  of 
a  flower  or  a  picture  or  even  a  complex  mental  resolution 
all  take  their  rise  in  definite  atomic  motions  or  collisions 
going  on  in  our  brains — but  these  changes  do  not 
constitute  or  explain  the  arising  thought  itself. 

A  man  is  but  an  aggregate  of  material  atoms — whirl- 
ing, wheeling,  colliding — in  ceaseless  change.  And  Science, 
before  she  can  pretend  to  have  solved  the  problem  of  life, 
must  explain  how  such  a  mere  aggregate  of  so  many 
pounds'  weight  of  carbon,  nitrogen,  phosphorus,  oxygen 
and  hydrogen  atoms  can  evolve  thought  and  conscious- 
ness by  the  mere  relative  movement  of  these  atoms. 

At  present  Science  has  no  standpoint  wherefrom  to 
plunge  into  such  mysteries  ;  she  has  no  sure  anchoring 
ground  from  which  to  venture  into  the  unsounded  depths 
of  Mind,  to  conceive  of  its  generation  and  flight.  She 
has  nothing  definite  to  lay  hold  of  in  such  shadowy  realms, 
nothing  to  grip  and  guide  her  experimentally  as  in  the 
more  material  sciences  such  as  chemistry  and  physics  and 
mechanics,  where  experiment  reigns  supreme. 

And  so,  in  spite  of  all  the  enormous  advances  of  Science 
within  the  last  few  centuries,  we  are,  apparently,  as  far  as 
ever  from  the  solution  of  the  great  mystery  of  life  itself. 

Even  to-day,  after  a'  century  of  strife,  Science  still 
knows  not  whether  Wordsworth  was  right  when  he  wrote 
the  grand  words  which  represent  the  intuitive  belief  of 
unnumbered  millions  of  the  human  race  : — 

"  Our  birth  is  but  a  sleep  and  a  forgetting ! 
The  Soul  that  rises  with  us,  our  life's  Star, 

Hath  had  elsewhere  its  setting 

And  cometh  from  afar. 

Not  in  entire  forgetfulness 

And  not  in  utter  nakedness 
But  trailing  clouds  of  glory  do  we  come 

From  God,  who  is  our  home." 


CHAPTER    II 

THE    ROMANCE    OF    SOME    SIMPLE    NITROGEN 
COMPOUNDS 

NITROGEN,  like  carbon,  forms  an  innumerable  multitude 
of  compounds.  So  numerous  are  they,  indeed,  that  a 
large  book  could  be  written  about  them  alone.  These 
compounds  are  among  the  most  important  known,  com- 
prising as  they  do  the  bodies  which  build  up  living 
matter,  explosives,  medicines,  drugs  and  dyes — in  a  word 
all  those  bodies  which  serve  the  thousand  and  one  wants 
of  civilised  peoples.  Interesting  as  the  subject  would  be, 
we  cannot  treat  of  these  substances  here.  I  wish  to  direct 
the  reader's  attention  to  some  quite  simple  nitrogen 
compounds,  which  are  of  surpassing  interest  at  the  present 
time. 

The  fate  of  a  world  probably  rests  upon  two  simple 
compounds  of  nitrogen — namely,  nitric  acid,  HNO3,  and 
ammonia,  NHg. 

This  is  a  fact  sufficient  to  direct  attention  to  these  two 
substances,  old  friends  of  our  schooldays  as  they  are, 
and  invest  them  with  a  fresh  interest.  Indeed  they  form 
the  centre  of  attention  of  the  scientific  world  at  the 
present  time,  since  it  is  directly  or  indirectly  from  these 
two  bodies  that  all  our  effective  explosives  are  made. 

Deprive  a  nation  of  them,  and  slowly  but  surely  her 
offensive  power  declines  and  ultimately  vanishes,  for  with 
them  goes  her  means  of  manufacturing  explosives.  More- 
over, her  supplies  of  food  must  dwindle  and  fall  far  below 

the  needs  of  any  congested  population,  because  nitrates 

24 


SOME    SIMPLE    NITROGEN    COMPOUNDS     25 

and  ammonium  salts  are  needed  by  the  land  for  manurial 
purposes,  to  supply  nitrogen  to  make  crops  grow. 

Let  us,  therefore,  first  of  all  concentrate  our  attention 
on  these  two-  substances.  Of  the  two  nitric  acid,  HNO3, 
has  possibly  the  greater  commercial  importance,  and  so 
we  will  take  that  first. 

It  is  a  colourless  liquid.  The  pure  acid  is  terribly 
corrosive,  attacking  organic  material  such  as  paper,  wood, 
and  skin  extremely  rapidly.  Most  metals  dissolve  in  it, 
evolving  poisonous  nitrous  fumes.  Moreover,  the  strong 
acid  is  decomposed  by  light,  evolving  oxygen  gas.  Hence 
if  an  air-tight  bottle  of  the  pure  acid  is  placed  in  a 
brightly  lighted  room,  enough  oxygen  may  be  gradually 
formed  to  cause  such  a  pressure  inside  that  the  bottle 
explodes  and  hurls  the  fluid  in  all  directions  on  to  the 
wooden  floors  and  benches.  When  this  occurs  invariably 
the  wood  takes  fire  and  burns  furiously.  Some  chemical 
laboratories  have  been  burnt  down  in  this  way.  The 
acid  is,  therefore,  always  preserved  in  dark  blue  bottles 
in  a  dark  place.  For  a  similar  reason  it  is  very  difficult 
to  send  pure  nitric  acid  in  large  quantities  long  distances 
by  rail.  For  if  the  glass  vessel  in  which  it  is  confined 
should  happen  to  break,  then  the  strong  acid  pouring 
over  the  waggon  almost  always  sets  it  alight.  Conse- 
quently the  substance,  when  in  large  quantities,  is  sent 
diluted  with  water.  In  the  colour  industry,  however, 
it  is  absolutely  necessary  to  have  a  very  strong  acid  free 
from  every  trace  of  water.  The,  difficulty  of  transporta- 
tion was  ultimately  got  over  by  mixing  the  strong  acid 
with  an  equal  volume  of  strong  sulphuric  acid.  The 
mixture  can  be  sent  in  iron  vessels,  and  consequently 
without  danger,  since  the  iron  becomes  "  passive  "  or  in- 
soluble in  acid,  owing  to,  some  authorities  say,  a  thin 
coating  of  iron  peroxide  forming  a  protecting  film  over  it. 

Owing    to  the  terribly  corrosive  properties  of    nitric 


26     MODERN  CHEMISTRY  AND   ITS  WONDERS 

acid  many  fearful  accidents  have  happened,  and  of  these 
the  most  dramatic  was  that  which  occurred  some  years 
ago  in  a  large  German  dye-factory.  A  workman  over- 
balanced himself  and  fell  into  a  large  vat  containing  a 
boiling  mixture  of  strong  nitric  and  sulphuric  acids,  such 
as  is  used  for  dissolving  dyes.  There  was  no  one  in  the 


FIG.  1. — Railway  trucks  set  on  fire  by  nitric  acid. 

building  to  hear  his  last  despairing  cry,  and  when,  later, 
the  man  was  missed,  nowhere  could  a  trace  be  found 
of  him.  His  vanishing  was  an  absolute  mystery  which 
no  one  could  account  for.  Some  people  thought  that 
the  man  had  secretly  fled  the  country  and  gone  to 
America,  others  that  he  had  met  with  an  accident.  The 
manager  of  the  works  suggested  that  he  had  fallen  into 


SOME    SIMPLE    NITROGEN    COMPOUNDS     27 

the  acid  and  had  been  dissolved,  hair,  flesh,  boots,  clothes, 
bones  and  all.  The  weeping  wife  now  laid  claim  to 
his  insurance  money,  but  the  assurance  officials  refused 
to  pay  out  anything.  "  Produce  us  evidence  of  death," 
they  said,  "  and  we  will  give  you  the  money.  How  do 
we  know  that  your  husband  has  not  simply  secretly  left  the 
country  ?  "  So  the  poor  widow  was  in  a  sad  plight  and 
at  her  wits'  end  what  to  do.  She  appealed  to  the  manager 
of  the  works,  and  he  resolved  to  solve  the  problem. 
Being  a  chemist,  he  knew  that  the  human  body  contains 
quite  a  considerable  amount  of  phosphorus,  which  must 
be  found  in  the  acid  (if  the  man  had  really  fallen  into  it) 
in  the  form  of  phosphoric  acid.  So  he  caused  an 
analysis  of  .the  liquid  to  be  made,  and  sure  enough  found 
a  large  amount  of  phosphorus  present,  such  as  repre- 
sented the  amount  known  to  be  in  the  body  of  a  full 
grown  man.  This  evidence  was  then  presented,  and 
the  end  of  it  all  was  that  it  was  accepted  as  conclusive 
evidence  of  death,  and  the  poor  widow  received  the  pay- 
ments due  to  her.  Applied  chemistry  is  thus  of  great  use, 
sometimes,  in  legal  matters,  although  lawyers  are  not, 
as  a  rule,  trained  in  such  matters. 

Nitric  acid,  being  one  of  the  most  important  of 
modern  chemicals,  is  manufactured  in  enormous  quan- 
tities. It  is  stated  that  more  than  100,000  tons  are  made 
annually — enough  to  form  a  lake  200  yards  square  and 
10  feet  deep.  At  the  present  time,  owing  to  the  war, 
far  greater  quantities  than  this  are  being  made. 

Nitric  acid  is  absolutely  indispensable  for  making  dyes 
and  explosives.  The  aniline  dye  industry — worth  millions 
of  pounds  annually — would  be  non-existent  without  nitric 
acid.  So  also  would  the  explosive  industry.  Almost 
every  high  modern  explosive  in  some  stage  or  other  in 
its  manufacture  requires  nitric  acid. 

Thus  nitro-glycerine — the  basis  of  dynamite,  cordite, 


28     MODERN   CHEMISTRY  AND   ITS  WONDERS 

blasting  gelatine  and  the  like — is  made  (p.  59)  by  bringing 
together  nitric  acid  and  glycerine.  Picric  acid  (the  basis 
of  lyddite,  mellinite  and  the  like)  and  trinitrotoluene,  so 
important  as  the  bursting  charge  of  modern  shells,  are 
obtained  by  allowing  nitric  acid  to  react  with  phenol  and 
toluene — substances  contained  in  coal  tar.  Ammonium 
nitrate — a  compound  of  nitric  acid  and  ammonia — is  the 
base  of  most  mining  explosives. 

Therefore,  deprive  a  nation  of  its  nitric  acid  and  you 
deprive  it  of  its  explosives  and  of  its  power  of  waging  war. 

Until  quite  recently  practically  the  only  source  of 
nitric  acid  was  Chile  saltpetre  (sodium  nitrate,  NaNO3). 
The  acid  was — and  still  is — obtained  from  this  by  heating 
it  in  iron  boilers  with  concentrated  sulphuric  acid  (oil  of 
vitriol),  when  the  following  change  takes  place : 

NaNO3     +      H2SO4      =        NaHSO4     +      HNO3 

Sodium  nitrate        Sulphuric  acid     Sodium  hydrogen  sulphate     Nitric  acid 

The  nitric  acid  which  distils  over  is  collected  in  earthen- 
ware vessels. 

Now,  until  quite  recently,  practically  the  world's 
whole  supply  of  nitrates  came  overseas  from  a  rainless 
and  desert  strip  of  land  lying  along  the  coasts  of  Chile 
and  Peru ;  it  was  long  ago  remarked  that  with  all  her 
strength  Great  Britain  could  be  put  out  of  commission  in 
war  times  simply  by  cutting  off  her  supply  of  nitrates 
from  Chile.  The  same  applied  with  even  greater  force  to 
Germany  and  the  Continent  of  Europe. 

In  England  at  the  time  of  writing  the  same  fact  holds 
to-day  ;  but  in  Germany  new  factors  have  come  upon  the 
scene,  and  she  no  longer  depends  to  the  same  extent  as 
formerly  upon  overseas  imports  of  nitrates.  Germany 
has  begun  to  make  her  own  nitrates  and  nitric  acid.  In 
my  former  book,  Triumphs  and  Wonders  of  Modern  Chemistry? 

1  2nd  ed.,  p.  196. 


SOME    SIMPLE    NITROGEN    COMPOUNDS     29 

I  explained  how  in  the  atmosphere  we  have  a  practically 
inexhaustible  supply  of  nitrogen — about  4000  billion  tons. 

Every  square  yard  of  land  has  about  seven  tons  of 
nitrogen  lying  over  it :  but  all  this  nitrogen  is  "  free  "  and 
therefore  useless  for  chemical  purposes.  We  have  to 
combine  it  or  " fix  it"  as  chemists  say,  before  we  can 
turn  it  into  useful  products. 

There  are  several  ways  of  doing  this.  In  the  first 
place  we  can  burn  the  nitrogen  of  the  air  directly  to 
nitric  acid  simply  by  causing  it  to  pass  through  a  high 
tension  electrical  arc.  How  this  was  done  was  briefly 
indicated  in  my  former  book,  but  the  subject  has  de- 
veloped since  then  and  so,  for  completeness'  sake,  some 
additional  details  are  here  given. 

The  various  processes  now  in  use  for  directly  burning 
the  air  to  nitric  acid  are  shown  diagrammatically  in  the 
accompanying  drawing,  which  is  taken  from  the  writer's 
Chemical  Lecture  Diagrams. 

Fig.  1  shows  a  general  view  of  the  plant.  A  is  the 
air  compressor,  which  forces  a  steady  stream  of  air  into 
the  electrical  furnace  B  (which  may  be  any  of  the  types 
shown  below).  Here  combination  of  nitrogen  and  oxygen 
occurs,  nitric  oxide,  NO,  being  formed,  thus  :  N2-fO2 
=  2NO  ;  and  the  gas  at  800-1000°  C.,  mixed  with  excess 
of  air,  passes  into  the  cooling  chamber  C,  and  then  along 
a  series  of  pipes,  D  D,  which  traverse  the  interior  of  a 
boiler,  F,  and  so  heat  it  sufficiently  to  cause  it  to  develop 
enough  steam  to  work  the  pumps,  &c. 

The  gas,  now  cooled  to  about  50°  C.,  enters  a  large 
oxidation  chamber,  G,  where  the  nitric  oxide,  NO,  finally 
unites  with  oxygen  still  present  in  the  air  to  form  nitrogen 
peroxide,  NO2,  thus:  NO  +  O  =  NO2,  and  the  chamber 
becomes  filled  with  the  brown  fumes  of  this  substance. 
Combination  has  not  occurred  before  because  in  C  the 
temperature  was  too  high  to  permit  of  the  existence  of 


30     MODERN   CHEMISTRY  AND   ITS  WONDERS 

NO2,    as     a    high     temperature    decomposes     it,    thus: 
NO  =NO  +  O.     The  nitrous  fumes  now  pass  along  the 


AIR  COMPRISE* 


FI6.I.GENERALVIEW OF  PLANT 

88B. 


1C 


NO 


NO, 


DJ^ 


T- If 


OXIDATION 
FURHACC  ST SAM  BOILER  CHAMBER 


FIG.3  BIRKEUND  EYDE  FURNACE  SECTION 


FIG.2.  BIRKELAND  EYDE  ELECTRIC  FURNACE 
(DIAGRAMMATIC) 

E 


_IR  ARC  FLAME 

ItMPlOYEDBYTMS 
;-ANIUN4SODA-rABKIK) 


FI6. 5.  PAULING  FURNACE 


Fl  G .  4 .  B I RKELAND-EYDC  FURNACE 
EXTERNAL  VIEW 


FIG.  2. — Nitric  acid  from  the  atmosphere. 

pipe  H    I   into  the  absorption  tower  K,  where  it  meets 

with    a    descending    stream    of    trickling    water.  This 

decomposes    the     nitrogen     peroxide,    forming    a  mix- 


SOME    SIMPLE    NITROGEN    COMPOUNDS     31 

ture  of  nitrous  and  nitric  acid,  thus :  2NO2  -f  H2O 
=  HNO2  +  HNO3.  This  liquid  can  be  drawn  off  and 
converted  into  pure  nitric  acid  by  driving  warm  air 
through  it  ;  but  more  usually  the  acid  liquids  are 
allowed  to  flow  into  a  series  of  tanks,  L,  rilled  with 
moist  limestone,  which  is  converted  into  a  mixture  of 
calcium  nitrate  and  -nitrite.  If  soda  or  potash  is  em- 
ployed as  the  neutralising  medium,  we  get  sodium  or 
potassium  nitrates  produced. 

Fig.  2  is  a  diagrammatic  sketch  of  the  Birkeland-Eyde 
furnace.  The  electrodes  consist  of  two  copper  pipes,  A 
and  B,  kept  cool  by  a  current  of  water.  They  are  con- 
nected  with  a  high-tension  powerful  alternating  current, 
which  forms  an  arc  between  them.  The  arc  is  placed 
between  the  poles  of  a  powerful  electro-magnet,  which 
then  blows  it  out  into  a  wheel-like  disc  of  flame  composed 
of  burning  oxygen  and  nitrogen.  The  whole  is  enclosed 
in  a  refractory  casing,  shown  in  section  in  fig.  3  and  a 
general  view  in  fig.  4.  The  section  fig.  3  shows  how  air 
is  blown  in  to  feed  the  flame.  The  air  enters  at  A  A  and 
passes  in  through  holes  in  the  refractory  lining.  The 
electric  flame  plays  down  the  disc-like  space  C  C,  and 
the  burnt  gases  come  out  at  D  and  then  pass  away  to 
the  absorption  plant,  as  indicated  in  fig.  1.  E  E  are  the 
wires  of  the  electro-magnets. 

Fig.  4  shows  how  the  Birkeland-Eyde  furnace  looks 
when  viewed  externally. 

Fig.  5  shows  the  Pauling  arc  flame.  The  main 
electrodes  A  and  B  are  bent  into  the  shape  of  a  V, 
A  H  H  being  a  section  of  one  main  electrode  and  B  K  K 
a  section  of  the  other.  The  base  of  the  electrodes  thus 
forms  at  M  N  a  vertical  slot,  through  which  are  intro- 
duced thin  "lighting  knives''  F  F.  These  "knives" 
can  be  brought  very  close  together  by  the  screwing 
arrangement  P  P,  and  the  arc,  thus  lighted  at  the 


32     MODERN   CHEMISTRY  AND   ITS   WONDEF 

narrowest  portion  of  the  spark  gap,  shows  a  tendency 
rise  up  between  H  H  and  K  K,  owing  mainly  to  1 
upward  pull  of  the  hot  gases,  but  is  interrupted  at  eve 
half  period  of  the  alternating  current,  only  to  be  reform 
at  the  lowest  and  narrowest  part  of  the  electrod 
Through  a  nozzle,  C,  a  stream  of  previously  heated  I 
air  is  blown  upwards  into  the  arc,  causing  the  air 
diverge  and  form  between  the  V-shaped  main  electroc 
a  flame  of  burning  O  and  N,  sometimes  a  metre  in  leng 

Fig.  6  shows  the  furnace  employed  by  the  Badisc 
Anilin  und  Soda  Fabrik,  making  use  of  the  Schonherr  ; 
flame.  A  A  is  an  insulated  high-tension  electrode,  1 
other  electrode  being  the  iron  piping  E  E,  into  whi 
A  A  projects.  An  arc  is  thus  formed  between  1 
electrode  A  A  and  the  iron  piping  ;  but  a  stream  of 
is  blown  in  peripherically  at  the  base  of  the  pipii 
through  a  series  of  orifices,  X  X,  in  such  a  way 
to  cause  a  rotating  movement  in  the  tube  E  E,  a 
a  whirling  flame  of  burning  O  and  N  to  run  up  i 
tube  E  E  E,  which  is  cooled  at  the  top  by  the  wat 
cooling  arrangement  F  F.  The  hot  nitrous  gases  stre; 
away  from  E  E,  down  the  external  pipes  H  H,  and 
out  into  the  plant  for  absorbing  the  nitrous  fumes.  1 
air  enters  the  furnace  at  C,  and  is  heated  to  a  hi 
temperature  before  being  blown  into  the  arc  (throu 
the  orifices  at  X)  by  passing  up  the  tube  D  D  and  do 
the  tube  B  B,  both  of  which  are  heated  by  the  hot  ga 
streaming  away  from  the  furnace. 

Now  the  main  disadvantage  of  all  processes  of  direc 
burning  up  the  atmosphere  is  the  very  poor  yield 
nitric  acid  for  the  power  applied.  Such  processes  c 
only  come  into  extended  use  in  lands  where  power 
cheap — especially  in  lands  rich  in  water  power,  wh 
is  especially  useful  for  the  production  of  the  elect 
current.  Hence  such  processes  have  mainly  develop 


SOME    SIMPLE    NITROGEN    COMPOUNDS     33 

in  countries  like  Norway,  Sweden  and  America,  where 
very  great  waterfalls  exist  (see  chap.  VIII.). 

Quite  recently,  therefore,  a  sensation  was  made  in 
the  scientific  world  when  it  became  known  that  nitric 
acid  can  be  made  quite  cheaply  from  ammonia  gas,  NHg, 
and  that  the  latter  in  its  turn  can  be  manufactured  quite 
cheaply  from  atmospheric  nitrogen  and  hydrogen,  as  we 
shall  presently  see. 

The  process  for  turning  ammonia  into  nitric  acid 
was  brought  to  perfection  by  the  famous  German  chemist 
Ostwald.  It  is  simplicity  itself — although  many  years  of 
patient  research  were  necessary  before  it  was  brought  to 
commercial  success.  The  ammonia  gas  is  mixed  with 
the  requisite  amount  of  oxygen  gas  and  the  whole  is 
sent  through  tubes  filled  with  a  preparation  of  finely 
divided  metallic  platinum,  which  here  acts  as  a  catalyst. 
The  temperature  must  be  very  carefully  regulated,  and 
when  this  is  done,  we  get  the  ammonia  quantitatively 

converted  into  nitric  acid  thus : 

• 

NH3    +    202    =    HN03    +    H20 

Ammonia        Oxygen      Nitric  acid  Water 

Thus  Germany's  power — due  entirely  to  scientific 
research — of  producing  nitric  acid  quite  cheaply  from 
ammonia,  renders  her  independent  of  the  saltpetre  beds 
of  Chile  for  the  supply  of  her  explosives.  In  fact,  were 
it  not  for  the  wonderful  development  of  chemical  science 
in  Germany,  it  is  quite  safe  to  say  that,  encircled  as  she 
is  by  a  ring  of  enemies,  Germany  would  have  been 
beaten  to  her  knees  in  a  few  months.  Her  supplies  of 
war  necessities  would  have  been  utterly  unequal  to  the 
demand.  She  could  not,  in  fact,  have  undertaken  the 
present  terrible  war  at  all.  It  is  German  science,  even 
more  than  German  armies,  which  has  made  her  a  menace 
to  the  neighbouring  nations.  It  has  given  her  such  a 

c 


34     MODERN    CHEMISTRY  AND    ITS  WONDERS 

powerful  command  over  matter,   that   she   can  produce 
most  of  her  own  supplies. 

But  this  brings  us  back  to  our  old  friend  ammoniay 
NH3,  and  we  must  now  say  a  few  words  regarding  this 
very  important  substance. 

Ammonia  gas  is  lighter  than  air  and  very  soluble  in 
water,  so  that  it  must  be  collected  by  displacing  the  air 
out  of  a  vessel  as  shown  in  the  illustration  (fig.  5). 
It  may,  of  course,  be  collected  over  mercury.  The  gas 
thus  obtained  is  colourless  and  invisible  but  possesses  a 
most  powerful  smell.  A  single  sniff  .of  it  will  bring  tears 
to  the  eyes  and  almost  suffocate  one.  Indeed  death  has 
been  known  to  follow  the  accidental  breathing  of  the 
vapour.  Ammonia  gas  is  so  soluble  in  water  that  at  0°  C. 
over  a  thousand  cubic  feet  of  it  will  be  condensed  within  a 
single  cubic  foot  of  water.  The  water  becomes  warm  as  the 
ammonia  dissolves  in  it  and  extends  so  as  to  double  its  bulk. 
It  is  very  probable  that  a  chemical  combination  takes  place, 
thus: 

NH3    +  H20-        NH4OH 

Ammonia      Water      Ammonium  hydroxide 

This  solubility  of  the  gas  may  be  shown  by  inverting 
a  jar  of  it  over  water.  This  rushes  up  and  completely 
fills  it.  A  striking  experiment  is  founded  upon  this  fact. 
If  a  bottle  filled  with  ammonia  gas  and  fitted  with  a  cork 
containing  a  tube  which  projects  up  inside  the  jar  (fig.  3), 
be  placed  over  water,  the  water  will  run  up  the  jet  and 
on  reaching  the  end  will  squirt  in  a  fountain  into  the 
interior  of  the  jar  until  it  is  full  of  water.  If  the  water 
be  coloured  red  with  litmus  solution,  this  will  turn  blue 
within  the  jar  owing  to  the  action  of  ammonia,  and 
we  get  a  red  fountain  of  water  changing  its  colour  to 
blue  in  a  most  striking  way.  The  first  drop  of  water 
which  reaches  the  inside  of  the  jar  absorbs  nearly  all  the 
ammonia  in  the  neighbourhood  and  thus  creates  a  partial 


SOME    SIMPLE    NITROGEN    COMPOUNDS     35 

vacuum  inside.  The  external  pressure  of  the  air,  pressing 
down  with  a  force  of  15  Ibs.  per  square  inch,  then  forces 
the  water  into  the  vacuous  vessel  with  such  force  that  it 
squirts  up  as  a  regular  fountain. 

The  gas  will  not  burn  in  air  unless  heated  strongly. 
Chemically  it  combines  with  acids,  neutralising  them  and 


FIG.  3. — Solubility  of  ammonia  in  water. 

forming  a  series  of  most  important  compounds  known  as 
the  ammonium  salts,  some  of  which  are  valuable  manures. 
The  solution  of  ammonia  in  water  is  what  is  termed  a 
"  base,"  because  it  has  these  properties  and  turns  red 
litmus  blue. 

Pressure  and  cold  turn  it  into  a  colourless  liquid  which 
boils  at  -38-5°  C.  and  freezes  at  -  77°  C.  to  a  mass  of 
white  transparent  crystals. 


36     MODERN   CHEMISTRY  AND  ITS  WONDERS 


Liquid  ammonia,  like  water,  absorbs  much  heat  when 
allowed  to  evaporate,  and  is  now  used  on  a  large  scale 
for  producing  cold  and  manufacturing  ice.  This  liquid 
ammonia  possesses  very  powerful  solvent  properties,  dis- 
solving as  a  rule  those  things  which  dissolve  in  water  and 
in  many  other  ways  behaves  like  water. 


FIG.  4. — Preparing  ammonia  by  heating  lime  and  ammonium  chloride. 

Ammonia  gas  is  easily  prepared  by  heating  together 
ammonium  chloride  and  slaked  lime,  when  the  following 
change  takes  place : 


2NH4C1 

Ammonium  chloride 


-       Ca(OH)2 

Slaked  lime 
(Calcium  hydroxide) 


=       CaCL      +  2NH. 


2H20 


Calcium  chloride      Ammonia       Water 


SOME    SIMPLE    NITROGEN    COMPOUNDS     37 

As  a  matter  of  fact,  very  large  amounts  of  ammonia 
are  manufactured  every  year  in  this  way  from  liquors 
which  are  formed  when  coal  is  distilled  for  the  purpose 
of  making  coal  gas.  The  coal  contains  a  considerable 
amount  of  nitrogen,  and  much  of  this  escapes  in  the 
form  of  ammoniacal  liquors,  which  when  collected  and 
heated  with  lime  evolve  the  ammonia  as  such.  Usually, 
however,  the  evolved  ammonia  is  absorbed  by  passing 
the  gas  into  sulphuric  acid,  when  the  valuable  ammonium 
sulphate  is  produced,  thus  : 

2NH3      +      H2S04      =      (NH4)2S04 

Ammonia          Sulphuric  acid  Ammonium  sulphate 

Thus,  even  in  1906  Great  Britain  produced  about 
290,000  tons  of  ammonium  sulphate,  and  Germany  about 
235,000  tons.  This  substance  found  its  main  use,  of 
course,  for  manurial  purposes,  as  plants  need  for  growth 
nitrogenous  food  quite  as  much  as  do  animals. 

However  such  quantities,  large  as  they  may  seem, 
are  much  too  small  to  meet  national  needs.  They  are 
a  mere  drop  in  the  ocean  of  the  world's  hunger  for 
nitrogenous  compounds.  Consequently,  a  great  sensation 
was  produced  in  chemical  circles  in  1913  when  it  be- 
came known  that  two  German  chemists,  namely  Haber 
and  Le' Rossignol,  had  succeeded  in  solving  the  problem 
of  how  to  make  free  nitrogen  and  free  hydrogen  unite 
directly  so  as  to  form  ammonia.  Of  course  it  had  long 
been  known  that  hydrogen  and  nitrogen  will  directly 
unite  under  suitable  conditions.  A  simple  experiment 
can  be  carried  out  to  prove  this. 

If  we  mix  hydrogen  and  nitrogen  gases  together  in 
the  proportion  of  three  volumes  of  hydrogen  to  one 
volume  of  nitrogen,  and  then  pass  a  series  of  electrical 
sparks  through  the  gaseous  mixture,  we  notice  that  it 


38     MODERN   CHEMISTRY  AND   ITS  WONDERS 

will  contract  and  form   the  strongly  smelling   ammonia 
gas : 

N2     +    3H2    =  2NH 

Nitrogen      Hydrogen      Ammonia 

How  electricity  achieves  this  is  not  known.  Perhaps 
the  intense  heat  of  the  electrical  spark  shatters  the 
hydrogen  and  nitrogen  molecules  into  single  atoms  which 
then  rush  together  to  form  ammonia  molecules. 

The  subject  is,  however,  probably  far  more  complex 
than  this.  It  is  known  that  under  the  influence  of  the 
electric  discharge  (which  we  must  picture  as  a  stream  of 
tiny  electrons  flying  like  projectiles  with  a  velocity  of 
thousands  of  miles  a  second  across  the  space  occupied 
by  the  whirling  gaseous  molecules),  centres  of  attraction 
appear  in  the  gas,  being  probably  composed  of  molecules 
or  atoms  which  have  captured  many  electrons.  To  them 
come  streaming  other  molecules  and  group  themselves  in 
thousands  around  the  centre  to  form  complicated  clusters. 
It  is  probably  in  these  clustering  groups  of  molecules  that 
those  collisions  occur  which  give  rise  to  the  formation  of 
ammonia  molecules.  Ultra-violet  light  will  bring  about 
the  same  result,  but  how  or  why  these  strange  changes 
take  place  remains  for  the  most  part  wrapt  in  mystery. 

However  this  may  be,  it  is  certain  that  any  such 
method  of  producing  ammonia  is  quite  hopeless  from 
a  commercial  standpoint — the  yield  of  ammonia  is  too 
bad. 

Now  Haber  and  Le  Rossignol  set  to  work  in  another 
way.  They  made  numerous  experiments,  and  discovered 
that  if  they  sent  hot  nitrogen  and  hydrogen  through 
tubes  containing  finely  divided  metallic  osmium  or  ura- 
nium the  two  gases  will  readily  unite  and  the  ammonia 
can  be  separated  from  the  gases  in  quantities  large 
enough  to  make  the  process  a  very  profitable  one.  The 


SOME    SIMPLE    NITROGEN    COMPOUNDS     39 

metallic  uranium  or  osmium  act  "  catalytically  " — that 
is  to  say,  they  cause  the  union  to  take  place  without 
themselves  undergoing  any  marked  chemical  change. 
Many  such  catalytic  actions  are  known  in  chemistry,  but 
how  these  "  catalysts  "  work  is  not  known. 

The  process  has  been  used  technically  on  a  large 
scale  in  Germany  by  the  Badische  Anilin  und  Soda  Fabrik, 
and  the  whole  process  forms  a  really  wonderful  feat  of 
scientific  chemical  engineering.  Stupendous  pressures 
are  used — the  gaseous  nitrogen  and  hydrogen  being 
compressed  to  about  200  atmospheres — 3000  Ibs.  on  the 
square  inch — and  all  leakage  under  this  enormous  pres- 
sure has  been  eliminated.  Many  of  the  details,  however, 
are  still  kept  secret,  and  it  is  known  that  works  costing 
over  £2,000,000  were  being  erected  in  Germany  in  1913 
for  the  production  of  ammonia  on  the  larger  scale. 

Owing  to  the  dangerous  pressures  employed,  it  is 
stated  that  many  of  the  working  parts  are  buried  in 
immense  trenches  so  that  the  disastrous  effects  of  an 
explosion  will  be  minimised.  The  nitrogen  is  obtained 
in  practically  unlimited  quantities  by  liquefying  the  air 
and  separating  the  oxygen  by  fractional  distillation,  as  ex- 
plained in  my  former  book,  Triumphs  and  Wonders  of  Modern 
Chemistry,  p.  183.  The  hydrogen  is  obtained  by  the 
decomposition  of  coal  gas  or  similar  gases,  or  by  passing 
steam  over  red-hot  iron,  or  by  passing  water  gas  over 
red-hot  lime,  for  in  fact  by  modern  methods  hydrogen 
can  be  obtained  in  practically  unlimited  quantities  and 
extremely  cheaply.1 

The  following  diagram,  fig.  5,  taken  from  the  author's 
Chemical  Lecture  Diagrams^  will  explain  the  method  em- 
ployed in  making  synthetic  ammonia. 

The  pump  M  forces  a  mixture  of  nitrogen  and  hydro- 

1  The  technical  processes  are  explained  at  length  in  the  author's    work, 
Industrial  Chemistry,  vol.  ii. 


40     MODERN  CHEMISTRY  AND    ITS  WONDERS 

gen  under  a  pressure  of  200  atmospheres  along  the  tube 
E  E  E  into  the  vessel  H,  whence  it  passes  out  through 
X  F  F  W  through  a  drier,  C  (filled  with  soda  lime),  into 
the  strong  tube  O  P,  as  shown.  A  is  an  electric  heater, 
whereby  the  gas  passing  along  the  inner  tube  S  T  is 
raised  to  a  temperature  of  800-1000°  C.,  and  then  passes, 
while  hot,  through  the  contact  substance  at  B  (usually 
finely  divided  osmium  or  uranium),  which  is  heated  by 
the  hot  gas  to  about  500-600°  C.  Here  combination 
between  the  hydrogen  and  nitrogen  takes  place,  and 
ammonia  is  formed.  The  tube  S  T  is  thus  kept  hot  by 
the  gas  streaming  down  it,  the  temperature  being  highest 
at  S  and  decreasing  as  we  proceed  towards  T.  Therefore 
the  cold  entering  gas,  as  it  comes  in  by  U  and  passes 
over  the  hot  tube  on  its  way  towards  S,  naturally  gets 
heated,  and  at  the  same  time  aids  in  cooling  the  tube 
from  T  to  a,  so  that  by  the  time  the  gas  passes  from 
U  to  S  it  is  almost  raised  to  the  temperature  of  the 
furnace  at  S,  whereas,  as  the  heated  gas  passes  down 
the  tube  S  T,  it  is  finally  so  chilled  by  the  incoming  gas 
at  U  that  it  issues  at  T  with  a  temperature  not  much 
higher  than  the  atmospheric.  The  interchange  of  heat 
is  thus  nearly  perfect.  The  mixture  of  uncombined  gas, 
together  with  the  produced  ammonia,  passes  along  the 
tube  N  R,  through  the  pump  M,  and  then  along  the 
tube  E  E  into  the  refrigerator  H.  H  is  surrounded  by 
a  vessel,  L  L,kept  at  a  temperature  of  -  60°  C.  to  -  70°  C. 
by  a  mixture  of  alcohol  and  solid  CO2 ;  and  at  this 
temperature  the  ammonia  gas  condenses  to  a  liquid  form, 
and  may  be  drawn  off  at  K.  The  cold,  gaseous  hydrogen 
and  nitrogen,  which  remains  uncondensed,  passes  away 
by  X  F  F,  and  here  meeting  the  entering  gas  coming 
down  the  interior  tube  E  E  chills  it  so  considerably 
that  it  enters  H  at  a  temperature  not  far  removed  from 
that  at  which  the  ammonia  condenses.  At  the  same 


SOME    SIMPLE    NITROGEN    COMPOUNDS     41 


42      MODERN    CHEMISTRY  AND    ITS  WONDERS 

time  the  gas  escaping  along  F  F  is  heated  almost  to 
atmospheric  temperature  by  the  incoming  gas,  and  so 
passes  away  through  a  drier,  C  (filled  with  soda  lime), 
into  U  almost  at  atmospheric  temperature. 

The  production  of  ammonia  in  this  way  is  fraught 
with  tremendous  economical  consequences.  Ammonium 
salts  will  become  much  cheaper  than  they  have  hitherto 
been,  and  so  the  price  of  nitrogenous  manures  will  fall 
greatly.  This  will  lead  to  a  revolution  in  many  branches 
of  agriculture,  and  intensive  farming  will  now  be  possible 
on  a  very  large  scale.  Hence  the  capacity  of  the  world 
to  produce  foodstuffs  will  increase  greatly,  so  that  a  long 
era  of  prosperity  should  lie  before  the  world — if  cheap 
and  sufficient  quantities  of  food  have  any  influence  on 
such  matters.  The  manufacture  of  all  sorts  of  expensive 
nitrogenous  compounds,  such  as  explosives,  dyes,  cellu- 
loid, photographic  films,  and  so  on,  will  also  be  enor- 
mously cheapened,  and  this  in  its  turn  will  make  other 
industries  develop,  and  these  will  react  one  on  the 
other  so  as  to  benefit  trade  and  commerce  in  a  way 
quite  incalculable  at  present.  Haber  and  Le  Rossignol's 
process  for  producing  synthetic  ammonia  represents  the 
foundation  of  a  world  industry,  whose  evolution  and 
development  will  profoundly  modify  the  conditions  of 
the  human  race. 

We  must  now  say  a  few  words  about  the  compounds 
of  nitrogen  with  oxygen — the  Oxides  of  Nitrogen. 

It  has  been  mentioned  in  a  previous  chapter,  nitrogen 
under  the  influence  of  an  electrical  discharge  will  burn  in 
oxygen,  producing  oxides.  There  exist  no  less  than  five 
of  these— namely ;  N2O,  NO,  NO2,  N2O3,  and  N2O5.  The 
first — nitrogen  monoxide,  N2O — is  a  colourless  gas  easily 
obtained  by  heating  ammonium  nitrate : 

NH4N03     =          N20          +2H2O 

Ammonium  nitrate      Nitrogen  monoxide       Water 


SOME    SIMPLE    NITROGEN    COMPOUNDS     43 

It  is  soluble  in  cold  water  but  less  so  in  hot.  Burning 
bodies  blaze  in  it  almost  as  brightly  as  in  oxygen  gas 
itself.  Its  great  peculiarity  consists  in  the  fact  that  when 
breathed  it  causes  insensibility.  While  coming  to,  the 
patient  will  utter  sounds  like  laughing.  Hence  the 
popular  j-name  -"laughing  gas."  It  is  much  used  by 


FIG.  6. — Dentist  administering  nitrogen  monoxide  to  a  patient. 

dentists  and  doctors  for  minor  surgical  operations.  If 
mixed  with  oxygen  and  breathed  for  a  short  time  it  will 
not  cause  insensibility  but  will  intoxicate  one  like  alcohol. 
Sir  Henry  Roscoe  thus  describes  its  effects  on  students 
working  in  a  chemical  laboratory  : l 

"At  the  end  of  the  session  of  laboratory  work  there 

1  Life  and  Experiences,  p.  35  (1906). 


44     MODERN    CHEMISTRY   AND    ITS  WONDERS 

was  held  by  the  students  what  may  be  termed  t  a 
chemical  saturnalia '  by  the  administration  of  nitrous 
oxide  (nitrogen  monoxide)  to  such  of  the  laboratory 
inhabitants  as  desired  to  take  it.  I  remember  very 
well  some  ludicrous  incidents,  interesting  in  showing 
what  varied  effects  the  nitrous  oxide  intoxication  pro- 
duces on  different  individuals.  The  Famulus  of  the 
laboratory  was  a  Quilp-like  creature,  Williams  by  name. 
When  under  the  influence  of  the  gas  he  simply  sat  upon 
the  coal  box  and  made  the  most  horrid  series  of  grimaces 
that  one  could  imagine.  Watts  (of  dictionary  fame)  on 
the  other  hand  when  under  its  influence  danced  about 
in  a  high  state  of  exhilaration,  clicking  his  thumbs  in 
great  delight.  A  student  of  the  name  of  Fox,  a  Quaker, 
and  of  course  a  man  of  peace,  became  terribly  pugnacious, 
and  chased  us  all  round  the  laboratory.  I  remember 
fortunately  hiding  behind  one  of  the  doors  in  the  furnace 
room,  but  he  caught  one  of  the  excisemen,  and,  getting 
the  head  of  the  unfortunate  man  <  into  chancery/  inflicted 
considerable  damage  upon  his  person.  It  was  all  over  in 
a  few  minutes,  but  it  was  deadly  while  it  lasted.  The 
astonishment  of  the  peaceable  Quaker,  when  he  recovered, 
at  the  results  of  his  onslaught  was  very  amusing  to  all  but 
the  exciseman." 

The  next  oxide — Nitric  oxide,  NO — is  also  a  colourless 
gas,  much  resembling  nitrogen  monoxide  in  general  pro- 
perties. Its  great  peculiarity  is  that  in  air  it  turns  red 
owing  to  its  combining  with  oxygen,  thus  : 

2NO     +    02    =        2N02 

Nitric  oxide       Oxygen       Nitrogen  peroxide 
(A  red  gas) 

It  may  be  prepared  by  pouring  strong  nitric  acid  upon 


SOME    SIMPLE    NITROGEN    COMPOUNDS     45 

copper  strips  or  shavings,  and,  being  insoluble,  may  be 
collected  over  water  ; 


3Cu  +  8HNO3=     2NO     +  3Cu(NO3)2  +  H2O 

Copper      Nitric  acid      Nitric  oxide       Copper  nitrate      Water 

The  gas  is  poisonous,  combining  with  the  haemoglobin, 
the  red  colouring  matter  of  the  blood,  to  form  a  compound 
which  prevents  it  from  fulfilling  its  function  of  oxygen 
carrier.  The  gas  is  even  more  deadly  than  carbon 
monoxide,  which  combines  in  a  similar  way  with  the 
Wood. 

The  substance  has  been  known  to  explode.  Indeed 
some  years  ago  a  quantity  of  the  gas  stored  up  in  an  iron 
structure  in  a  chemical  works  exploded  when  a  workman 
merely  turned  a  tap,  and,  blowing  the  apparatus  to 
pieces,  killed  the  unfortunate  man.  It  was  probably  re- 
solved into  free  nitrogen  and  oxygen. 

The  third  oxide  —  Nitrogen  peroxide,  NO2  —  is,  under 
ordinary  circumstances,  a  red  gas.  It  exists,  however,  in 
two  forms.  Below  —  10°  C.  it  forms  a  colourless  liquid 
having  the  formula  N2O4.  Above  this  temperature  it 
begins  to  break  down  into  N'O2,  changing  colour  as  it 
does  so,  and  becoming  dark  red.  The  red  fumes  noticed 
when  nitric  acid  or  nitrates  are  heated  are  due  to  the  forma- 
tion of  this  substance.  It  may  be  prepared  by  heating 
lead  nitrate. 

Pb(N03)2  =       PbO        +        2N02        +    02 

Lead  nitrate       Lead  monoxide      Nitrogen  peroxide      Oxygen 

The  substance  is  a  terrible  and  insidious  poison. 
Many  a  man  has  breathed  it  without  at  the  time  noticing 
any  bad  effects,  but  after  some  hours  or  even  days  a  pain 
may  develop  in  the  region  of  the  lungs,  a  violent  in- 
flammation may  set  in,  and  death  through  pneumonia 
follow.  The  reason  is  that  the  water  in  the  lungs  decom- 


46     MODERN   CHEMISTRY  AND    ITS  WONDERS 

poses  it,  forming  nitric  and  nitrous  acids,  both  terribly 
corrosive,  and  these  cause  wounds  in  the  tissues  and  set 
up  the  inflammation. 

2N02         +  H20=HN03  +    HN02 

Nitrogen  peroxide      Water      Nitric  acid      Nitrous  acid 

This  fact  is  rather  interesting,  because  when  modern 
explosives  detonate  large  amounts  of  nitrogen  oxides  are 
evolved  and  soldiers  breathing  such  fumes  are  very  liable 
fatally  to  injure  their  lungs.  (See  p.  78.) 

Of  the  remaining  oxides,  Nitrogen  trioxide,  N2O3,  is  a 
very  unstable  blue  liquid,  which  freezes  to  green  crystals, 
and  above  -  20°  C.  it  decomposes  to  NO  and  NO2.  While 
nitrogen  pentoxide,  N2O5,  is  a  colourless  solid,  which  ex- 
plodes when  suddenly  heated,  and  dissolves  in  water,  pro- 
ducing nitric  acid  : 


It  may  be  produced  by  distilling  strong  nitric  acid  with 
phosphorus  pentoxide. 

For  ages  in  the  past  a  terrible  and  mysterious  poison 
now  called  Hydrocyanic  or  Prussic  acid  has  been  known 
to  exist.  It  was  extracted  from  crushed  peach  stones  or 
leaves,  by  allowing  them  to  remain  soaked  in  water  for 
some  time  and  then  distilling  the  liquor.  The  first  part  of 
the  liquor  which  distilled  over  contained  the  poison.  In 
ancient  Egypt  some  four  thousand  years  ago  it  was  used 
for  putting  people  to  death.  Thus  on  a  papyrus  pre- 
served at  the  Louvre,  M.  Duteil  read,  "  Pronounce  not 
the  name  of  I.  A.  U.,  under  the  penalty  of  the  peach!" 
in  which  dark  threat,  without  doubt,  lurks  the  meaning 
that  anyone  who  revealed  the  religious  mysteries  of  the 
priests  would  be  put  to  death  by  waters  distilled  from  the 
peach.  "That  the  priests  actually  distilled  the  peach 


SOME    SIMPLE    NITROGEN    COMPOUNDS     47 

leaves,"  says  Blyth,1  "  has  been  doubted  by  those  who 
consider  the  art  of  distilling  a  modern  invention  ;  but  this 
process  was  well  known  to  adepts  of  the  third  and  fourth 
centuries,  and  there  is  no  inherent  improbability  in  the 
supposition  that  the  Egyptians  practised  it.  From  the 
Egyptians  the  knowledge  of  the  deadly  drink  appears  to 
have  passed  to  the  Romans,  for,  although  not  expressly 
mentioned,  yet  the  fact  that,  in  the  reign  of  Tiberius,  a 
Roman  knight,  accused  of  high  treason,  swallowed  a  poison 
and  fell  dead  at  the  feet  of  the  senators,  is  wholly  inexplic- 
able, unless  it  be  allowed  that  the  fatal  dose  was  prussic 
acid,  and  that  in  a  tolerably  concentrated  form."  Indeed 
it  is  believed  that  this  was  the  actual  poison  used  by 
Nero  to  get  rid  of  his  brother  Britannicus,  for  the 
details  of  this  tragedy  have  been  recorded  with  some 
minuteness. 

"  It  was  the  custom  of  the  Romans  to  drink  hot  water, 
a  draught  nauseous  enough  to  us,  but,  from  fashion  or 
habit,  considered  by  them  a  luxury,  and,  as  no  two  men's 
tastes  are  alike,  great  skill  was  shown  by  the  slaves  in 
bringing  the  water  to  exactly  the  degree  of  heat  which 
their  respective  masters  found  agreeable.  The  children 
of  the  imperial  house,  with  others  of  the  great  Roman 
families,  sat  at  the  banquets  at  a  smaller  side  table,  while 
their  parents  reclined  at  the  larger.  A  slave  brings  hot 
water  to  Britannicus  ;  it  is  too  hot ;  Britannicus  refuses 
it.  The  slave  adds  cold  water  ;  and  it  is  this  cold  water 
which  is  supposed  to  have  been  poisoned:  in  any  case, 
Britannicus  had  no  sooner  drunk  of  it  than  he  lost  voice 
and  respiration.  Agrippina,  his  mother,  was  struck  with 
terror,  as  well  as  Octavia,  his  sister.  Nero,  the  author 
of  the  crime,  looks  coldly  on,  saying  that  such  fits  often 
happened  to  him  in  infancy  without  evil  result ;  and  after 

1  Poisons :    Their  Effects  and  Detection,  by  A.  W.  Blyth,  p.  2.     Published 
by  Griffin  &  Co. 


48     MODERN   CHEMISTRY  AND   ITS  WONDERS 

a  few  moments'  silence,  the  banquet  goes  on  as  before."  l 
In  the  light  of  modern  science  we  know  that  the  poison 
must  have  been  either  prussic  acid  or  one  of  its  salts. 
The  effects,  indeed,  of  the  poison  are  appalling  in  their 
suddenness.  A  few  drops  placed  in  the  eye  of  a  dog 
kill  it  in  thirty  seconds.  A  man  has  been  known  to 
swallow  a  quantity  of  the  acid,  stagger  a  few  paces,  and 
fall  dead  without  a  sound  or  convulsion.  Usually,  how- 
ever, the  poisoned  person  falls  to  the  ground  in  convul- 
sions, and  dies  in  a  few  minutes. 

This  terrible  substance  is  known  now  to  be  a  simple 
compound  of  hydrogen,  carbon,  and  nitrogen,  having  the 
formula  HCN.  The  pure  acid  when  free  from  water  is 
a  colourless  extremely  volatile  liquid.  It  has  a  very 
peculiar  peach-blossom  odour  and  is  a  strong  acid. 
Usually  it  is  met  with  dissolved  in  large  excess  of  water. 
It  may  be  prepared  by  distilling  any  cyanide  with 
dilute  sulphuric  acid,  and  condensing  the  evolved  gas 
in  a  suitable  glass  vessel  in  water.  Yet  on  account  of 
its  terribly  poisonous  nature  (a  mere  sniff  of  the  vapour 
having  had  fatal  results)  only  very  skilled  chemists  should 
undertake  its  preparation.  It  seems  almost  incredible 
that  the  famous  Swedish  chemist  Scheele,  who  first  pre- 
pared it  pure  by  distilling  potassium  ferrocyanide  with 
sulphuric  acid  in  1782,  should  have  been  totally  unaware 
that  he  was  dealing  with  the  most  powerful  of  all  known 
poisons.  Thus  we  read  with  astonishment  that  he  smelt 
and  tasted  it,  and  did  various  other  experiments  with  it 
without  ill  effects. 

Free  prussic  acid  occurs  in  the  unripe  berries  of 
certain  plants.  It  there  serves  as  a  protective  means  to 
prevent  them  from  being  eaten  while  still  unripe  by 
birds.  The  curious  part  of  the  matter  is  that  as  soon  as 
some  of  these  berries  are  ripe,  the  prussic  acid  disappears, 
1  Blyth,  loc.  cit.,  p.  6. 


SOME    SIMPLE    NITROGEN    COMPOUNDS     49 

as  there  is  no  longer  need  of  protection.  In  many  plants 
and  natural  oils,  especially  in  bitter  almonds,  it  occurs 
not  free  but  combined  with  a  sugar,  forming  a  complex 
compound  called  amygdalin.  By  boiling  with  acids,  or 
even  on  prolonged  standing  with  water  in  the  presence 
of  certain  ferments  or  enzymes,  the  acid  is  set  free. 

The  salts  of  the  acid  form  a  very  interesting  and  im- 
portant class  of  bodies,  which,  however,  we  cannot  discuss 
further  here. 

Before  concluding  this  chapter  a  few  words  must  be 
said  regarding  an  interesting  gaseous  compound  of  nitrogen 
called  Cyanogen.  This  in  some  respects  is  allied  to  hydro- 
cyanic acid,  having  the  formula  C2N2,  although  it  is  a 
colourless  substance  not  having  any  acid  properties.  It 
was  discovered  by  Gay-Lussac  about  a  hundred  years  ago, 
who  prepared  it  by  heating  the  cyanides  of  gold,  silver, 
and  mercury,  thus : — 

Hg(CN)2    =    Hg    +   C2N2 

Mercury  cyanide      Mercury      Cyanogen 

The  mercury  salt  is  placed  in  a  hard  glass  tube  fitted 
with  a  cork  and  gas-delivery  tube.  At  a  dull  red  heat 
the  gas  is  rapidly  evolved  and  may  be  collected  over 
mercury,  being  somewhat  soluble  in  water. 

The  colourless  gas  seen  to  collect  over  the  mercury 
possesses  a  smell  somewhat  like  that  of  peach-blossoms, 
and  when  a  light  is  applied  to  the  mouth  of  the  vessel 
containing  it,  it  is  seen  to  burn  with  a  magnificent  purple 
flame.  It  is  terribly  poisonous,  a  breath  or  two  of  it 
being  fatal.  At  the  very  highest  temperatures  carbon 
and  nitrogen  appear  capable  of  directly  uniting,  cyanogen, 
for  example,  appearing  in  the  gases  evolved  from  blast 
furnaces.  It  is  supposed  by  some  authors  that  it  exists 
on  the  sun.  In  eclipses  of  the  sun  Hale  has  observed 
cyanogen  gas  floating  immediately  above  the  layer  of 

D 


50     MODERN   CHEMISTRY  AND    ITS  WONDERS 

white  hot  clouds  which  girdle  the  sun.  Probably  it  occurs 
in  far  greater  masses  beneath  these  clouds,  where  it  is  in- 
accessible to  observation.  If  it  thus  occurs  in  the  sun 
it  must  probably  have  existed  once  upon  a  time  in  the 
primeval  atmosphere  of  the  earth.  It  certainly  occurs 
in  comets.  In  the  tail  of  the  last  comet  (Comet  More- 
house)  the  spectroscope  discovered  traces  of  this  deadly 
gas,  and  it  has  been  suggested  that  the  passage  of  a 
large  comet  through  the  solar  system  may  cause  such  an 
irruption  of  this  substance  into  the  earth's  atmosphere 
from  external  space  that  the  whole  human  race  would 
be  poisoned.1  Although  not,  I  suppose,  inconceivable, 
such  an  event  is  very  improbable,  the  largest  comet  yet 
discovered  bearing  with  it  a  quantity  of  matter  far  too 
small  appreciably  to  affect  the  earth.  However,  it  is  by 
no  means  impossible  that  in  space  there  exist  worlds 
whose  atmospheres  contain  large  amounts  of  this  gas, 
and  whose  seas  are  impregnated  with  prussic  acid.  The 
faintest  breath  of  their  atmospheres,  and  the  slightest 
gulp  of  their  waters  would  instantly  prove  fatal  to  any 
creature  built  on  lines  similar  to  those  found  upon  the 
earth. 

1  Several  novels  have  been  written  in  which  the  supposition  is  made  that  in 
its  journey  through  space  the  earth  dashes  into  such  poisonous  vapour,  which 
kills  off  everything  except  the  heroes  and  heroines  of  the  story,  who  have  an 
exciting  time  exploring  the  dead  world  and  starting  it  anew. 


CHAPTER    III 

THE    ROMANCE    OF    EXPLOSIVES 

HUMAN  civilisation  is  very  old,  so  old  that  its  very 
beginnings  are  lost  in  the  mists  of  antiquity.  Thousands 
of  years  before  London  or  even  Troy  was  founded, 
there  existed  huge  world-cities,  with  their  swarming 
millions  of  inhabitants,  their  long  broad  paved  streets, 
their  countless  shops  and  stately  palaces.  Such  indeed 
were  Babylon,  Nineveh,  Ur  and  Nippur,  the  ancient 
wonder  cities  of  Mesopotamia,  some  four  thousand  years 
ago.  Their  remains,  buried  under  the  dust  mounds  of 
ages,  are  now  being  laboriously  excavated.  Indeed  the 
modern  traveller  when  passing  over  the  desolate  and 
silent  wastes  of  sand  which  now  cover  their  ruins  can 
scarcely  realise  that  he  is  standing  on  a  place  where 
thousands  of  years  ago  reigned  the  most  intense  human 
activity.  He  can  stand  on  the  very  spot  where — 

"  Once  Babylon,  by  beauty  tenanted, 
In  pleasure  palaces  and  walks  of  pride, 
Like  a  great  scarlet  flower  reared  her  head, 
Drank  to  the  sun,  and  laughed,  and  sinned,  and  died." 

But  all  that  he  will  see  of  her  one-time  mighty  fortifi- 
cations and  colossal  buildings,  which  towered  up  into  the 
air  to  the  height  of  600  feet,  are  a  few  unsightly  mounds 
of  earth. 

Centuries  before  Christ,  great  commercial  cities  like 
Tyre,  Sidon,  and  Carthage  were  built  of  rows  of  streets 
of  stately,  six-storied,  stone  houses,  while  thousands  of 

51 


52      MODERN   CHEMISTRY   AND   ITS  WONDERS 

trading  ships  rode  at  anchor  in  their  harbours  or  were 
moored  along  their  broad,  busy  quays. 

Civilisation  reached  a  high  level  in  ancient  Egypt. 
Some  of  the  engineering  works  carried  out  by  the 
Egyptians  still  remain  unsurpassed,  the  wonder  of  the 
modern  world.  Crete,  thousands  of  years  before  our 
era,  was  the  theatre  of  a  wonderful  civilisation,  the  very 
memory  of  which  had  faded  like  a  dream  from  the 
memory  of  men  until,  a  few  years  ago,  the  ruins  of  great 
palaces  were  unearthed,  whose  charred  remains  tell  us 
of  wars  unrecorded  and  forgotten  in  which  this  civilisa- 
tion perished. 

Ages  later,  and  still  in  the  memory  of  all,  arose  and 
spread  the  splendid  civilisations  of  Greece  and  Rome. 
America,  too,  even  in  very  early  times,  seems  to  have 
from  time  to  time  witnessed  the  periodical  rise  and  fall 
of  native  civilisations.  A  common  fate  overtook  these 
old  civilisations.  One  after  another  they  perished, 
overwhelmed  by  armies  of  warlike  savages.  Time  after 
time  this  has  happened,  not  only  in  Asia,  but  also  in 
Europe  and  America.  Every  time  settled  life  and  pro- 
gress began  in  any  region  of  the  world,  when  towns 
began  to  grow  up,  wealth  and  trade  develop,  and  plenty 
and  prosperity  to  smile  throughout  the  land,  then  thrift- 
less savages  in  neighbouring  districts,  scorning  to  obtain 
by  patient  labour  what  might  be  taken  by  force  of  arms, 
came  pouring  in  upon  the  bright  spot,  and  usually  suc- 
ceeded in  destroying  so  completely  the  beginnings  of 
civilisation  in  these  regions,  that  we  are  often  ignorant 
to  this  very  day  that  they  ever  existed.  The  world's 
history — or  rather  that  fragment  of  it  with  which  we  are 
acquainted — is  one  vast  tragedy.  And  the  reason  is 
simple  enough.  A  civilised  man  is  not  and  never  will 
be  a  match  physically  for  savages  living  under  wilder 
and  harder  conditions.  The  very  conditions  of  civilisa- 


THE    ROMANCE    OF    EXPLOSIVES  53 

tion  set  a  premium  upon  a  high  intelligence  and  a  weak 
muscle,  and  the  process  of  evolution  in  a  very  short 
time  produces  a  type  of  man  corresponding  to  this  want. 
But  among  savages  intellect  is  at  a  discount.  It  is  the 
fighting  man,  the  man  with  strength  and  courage,  who  is 
esteemed  and  valued,  and  consequently  produced  by  the 
conditions  of  life  under  which  he  exists.  Unless,  there- 
fore, a  civilised  state  can  compensate  the  physical  dis- 
advantages of  its  warriors  by  artificial  aids  such  as  a 
superior  organisation,  powerful  fortifications,  and  offen- 
sive death-dealing  machinery,  sooner  or  later  this  state  is 
bound  to  perish  in  hand-to-hand  conflicts  with  ruder  and 
less  civilised  nations  ;  and  thus  the  advances  it  has  made 
in  the  art  of  life  are  all  swept  away  again.  This  being 
so,  we  may  well  inquire  whether  the  modern  European 
civilisation  will  also  perish  in  the  same  way  ?  We  believe 
not.  It  is  possible  that  our  civilisation  will  suffer  a  slow 
process  of  internal  decay  as  the  result  of  the  spread  of 
some  religious  mania,  such  as  has  happened  in  the  East 
time  after  time,  and  in  the  West  once  at  least ;  but  violent, 
abrupt  dissolution  at  the  hands  of  savages  is  now  unthink- 
able. And  the  reason  is  simple.  Behind  each  civilised 
man  now  stands  a  power  a  million  times  mightier  than 
the  strongest  arm  that  ever  drew  a  sword  or  hurled  a 
spear — the  terrible  power  of  modern  explosives.  The 
bravest  savage  is  as  defenceless  as  a  rabbit  before  civilised 
man  with  his  lyddite  shells  and  quick-firing  guns.  Un- 
civilised races  can  manufacture  swords  and  spears  and 
arrows  of  the  materials  found  abundantly  about  them. 
But  the  manufacture  of  explosives  and  of  arms  of  precision 
is  utterly  beyond  their  power  ;  for  their  production  re- 
quires a  knowledge  of  chemistry  and  of  engineering 
science  such  as  is  unattainable  by  any  uncivilised  people. 
Indeed  a  people  arriving  at  such  knowledge  must  neces- 
sarily attain  civilisation  at  the  same  time.  Under  modern 


54     MODERN   CHEMISTRY   AND  ITS  WONDERS 

conditions  a  civilised  race  can  only  be  overcome  by  a 
civilised  race.  Nay,  more  ;  we  may  well  doubt  whether 
at  the  present  time  a  civilised  race  can  be  overcome  even 
by  a  civilised  race.  A  nation  like  Germany,  governed  by 
military  despots  drunk  with  an  imaginary  superiority,  may 
try  to  overrun  the  world.  But  her  only  chance  was  to 
take  the  world  by  surprise,  to  deliver  a  swift,  assassin-like 
blow  in  the  midst  of  smiling  peace,  and  overwhelm 
the  other  nations  while  these  were  unprepared  for  war. 
Give  but  a  breathing  time,  and  civilisation  puts  such 
terrible  defensive  weapons  in  the  hands  of  the  defenders, 
and  such  mighty  economic  forces  into  motion,  that 
such  efforts  are  brought  to  nought.  Napoleon  took 
fifteen  years  to  kill  a  million  men  ;  Kaiser  William  the 
Mad,  in  his  attempt  to  wreck  a  continent,  killed  two 
millions  of  men  in  twelve  months,  and  into  the  vortex  of 
the  titanic  struggle  sucked  thirty  millions  of  armed  men. 
Such  are  the  forces  which  modern  civilisation  opposes  to 
those  who  try  the  methods  of  savages  and  endeavour  to 
take  by  force  that  which  is  not  theirs  by  right  of  labour. 
Modern  science  has  rendered  as  true  now  as  ever  it  was, 
the  old,  old  saying  that  "  he  that  taketh  the  sword  shall 
perish  by  the  sword." 

Thus  we  owe  our  safety  to  explosives,  and  in- 
directly to  the  chemist  who  produces  them.  It  was 
said  of  old  that  the  pen  is  mightier  than  the  sword. 
We  can  now  say  with  truth  that  the  balance  of  the 
chemist  is  mightier  than  either.  The  nation  that  leads 
in  chemistry  leads  in  all  other  things,  for  upon  this 
science  there  depend  not  only  the  means  of  pro- 
ducing metals  for  making  machinery  and  tools,  but 
also  the  production  of  materials  from  which  are  made 
clothes,  books,  inks,  paint,  dyes,  medicines,  and  fire  itself 
— in  a  word,  all  that  distinguishes  our  life  from  that  of 
prehistoric  savages. 


THE    ROMANCE    OF    EXPLOSIVES  55 

But  here  the  reader  will  require  to  know  what  we  mean 
by  an  "  explosive."  Any  body  which  will  suddenly  expand 
and  exert  great  force  in  so  doing  may,  in  a  sense,  be 
called  explosive.  Even  such  a  harmless  liquid  as  water 
can  be  made  to  act  as  a  powerful  explosive.  The  most 
terrific  natural  explosions  which  occur  on  the  earth 
are  caused  by  it.  When  water  is  brought  into  contact 
with  white-  or  red-hot  material  it  is  suddenly  converted 
into  steam  which  may  occupy  several  thousand  times 
the  volume  of  water  from  which  it  was  produced,  and 
if  restrained  from  so  doing  will  exert  an  enormous 
force. 

The  terrible  volcanic  explosions  which  occur  from  time 
to  time,  and  fill  the  world  with  awe  and  terror,  are  due,  as 
a  rule,  to  water  coming  into  contact  with  the  white-hot 
matter  in  the  interior  of  the  earth.  Whole  mountains 
and  islands  have  by  this  means  been  blown  into 
the  air  with  a  tremendous  crash.  Thus  at  Krakatoa  in 
1883  a  whole  mountain,  forming  more  than  a  cubic  mile 
of  solid  rock,  was  hurled  into  the  air.  The  vast  thunder  of 
the  explosion  was  heard  nearly  2000  miles  away,  while 
windows  were  shattered  by  the  mighty  sound-waves  at 
a  distance  of  150  miles!  In  comparison  with  this,  the 
most  awful  of  artificial  explosions  produced  by  modern 
high  explosives  seem  quite  puny.  Thus  in  1896  some 
55  tons  of  blasting  gelatine  were  being  unloaded  from  a 
railway  train  at  Johannesburg  in  South  Africa,  when  it 
exploded  as  the  result  of  an  end-on  collision.  The  town 
was  startled  by  the  sound  of  a  titanic  thunderclap,  and 
looking  upwards  saw  a  sheet  of  flame  accompanied  by 
a  cloud  of  flying  debris  ascending  to  the  sky.  Rushing 
to  the  spot,  the  townspeople  found  that  a  crater  300  feet 
long,  65  feet  broad,  and  30  feet  deep  had  been  produced 
in  the  soft  ground,  while  every  building  within  a  radius  of 
1000  yards  was  either  blown  down  or  badly  shattered. 


56     MODERN   CHEMISTRY   AND   ITS  WONDERS 

About  30;000  tons  of  material  had  been  blown  into 
the  air. 

In  1893  the  Hudson  River  Palisades  were  blown  up 
at  Fort  Lee,  and  there  2  tons  of  dynamite,  placed  in  a 
chamber  in  the  rock,  brought  down  100,000  tons  of  rock. 
In  the  same  year  2^  tons  of  dynamite,  placed  in  chambers 
in  a  dyke  at  the  Dinoric  quarries  at  Llanberis,  blew  up 
180,000  tons  of  rock;  while  at  Talcen  Mahr  in  1895, 
7  tons  of  powder  poured  into  two  shafts  overthrew  nearly 
200,000  tons  of  material.  Yet  what  are  these  results 
when  compared  with  the  explosion  which  at  Krakatoa  blew 
into  the  air  some  seven  thousand  million  tons  of  rock 
and  earth  ! 

All  modern  explosives  are  solid  or  liquid  substances 
which  are  capable  of  suddenly  liberating  large  quantities 
of  gas  as  the  result  of  extremely  rapid  chemical  action. 
These  gases  set  up  a  tremendous  pressure,  and  so  blow  out 
the  bullet  from  the  gun  with  enormous  force  in  exactly 
the  same  way  that  the  compressed  air  of  a  boy's  air-gun 
does.  The  explosion,  or  the  sudden  conversion  of  a  solid 
or  liquid  into  gas,  is  effected  by  the  application  of  heat, 
electricity,  or  simple  percussion. 

The  explosive  best  known  to  us  all  is  Gunpowder.  This 
consists  of : 

Potassium  Nitrate,  KNO3      .          .          75  parts 
Charcoal,  C          .          .          .          .          15      „ 
Sulphur,  S 10      „ 

The  finely-powdered  materials  are  thoroughly  mixed 
together  in  gun-metal  or  copper  drums,  having  blades  in 
the  interior  capable  of  working  in  the  opposite  direction 
to  that  in  which  the  drum  itself  is  travelling.  After  passing 
through  a  sieve  the  mixture  is  then  ground  under  heavy 
metal  rollers,  subjected  to  hydraulic  pressure,  and  then 


THE  ROMANCE  OF  EXPLOSIVES     57 

broken  up  into  a  form  suitable  for  the  particular  purpose 
for  which  the  powder  is  intended. 

The  explosion  is  due  to  the  fact  that  the  elements  of 
the  potassium  nitrate  are  dissociated  by  heat,  gaseous 
oxygen  and  nitrogen  being  set  free.  The  nascent  oxygen 
combines  with  the  carbon  to  form  the  gases  carbon  mon- 
oxide (2C  +  O2  =  2CO)  and  carbon  dioxide  (C  +  O2  =  CO2). 
The  sulphur  should  unite  with  the  potassium  to  form  solid 
sulphide  of  potassium  according  to  the  equation : 

2KNO,      +     S     +   3C    =      3CO2 

o  £ 

Potassium  nitrate      Sulphur      Carbon       Carbon  dioxide 
(saltpetre) 

+      K2S     +     N2 

Potassium      Nitrogen 
sulphide 

But  as  a  rule  it  unites  with  some  oxygen,  producing  the 
gas  sulphur  dioxide  (S  +  O2=SO2).  The  gases  formed  by 
the  explosion  of  a  given  bulk  of  gunpowder  occupy  about 
300  times  the  bulk  of  the  powder  at  ordinary  tempera- 
tures. The  enormous  heat  produced  by  the  sudden  in- 
flammation expands  these  gases  many  times  further. 
To  this  expansion  the  explosive  force  is  due.  The  force 
set  up  may  be  reckoned  as  some  hundreds  of  tons  per 
square  inch.  Moreover,  as  the  powder  burns  rapidly  this 
pressure  is  suddenly  applied,  and  has  all  the  effect  of  a 
tremendous  blow.  The  chamber  in  which  the  bullet  is 
confined  gives  way  at  its  weakest  point.  Hence  the  bullet 
yields  before  the  breech,  and  is  hurled  with  a  mighty 
force  from  the  barrel.  This  is  not  always  the  case : 
fearful  accidents  sometimes  occur  when  the  ball  has  been 
too  tightly  wedged,  or  when  the  metal  of  the  breech 
is  weak. 

In  the  atomic  world  we  must  picture  the  explosion  as 
consisting  in  millions  upon  millions  of  gaseous  molecules 
bursting  forth  from  the  flaming  surface  of  the  powder 


58     MODERN   CHEMISTRY   AND    ITS  WONDERS 

and  flying  swiftly  against  the  bullet,  whirling  as  they 
fly  with  incredible  velocities.  Then,  just  as  one  billiard 
ball  imparts  motion  to  another,  so  also  do  each  of 
the  myriads  of  molecules  imparts  theirs  to  the  projectile. 
The  motion  imparted  by  a  single  molecule  may  be  as 
nothing,  yet  the  accumulated  effect  of  untold  millions  of 
impacts  is  stupendous.  The  projectile  acquires  an  ever- 
increasing  motion,  until  it  finally  rushes  forth  from  the 
barrel  and  flies  shrieking  through  the  air  on  its  errand  of 
destruction.  The  whole  complex  change,  the  sudden 
shattering  of  countless  millions  of  atomic  systems,  passes 
in  a  flash  beneath  our  eyes.  Yet,  as  I  have  pointed  out 
in  my  former  book,1  a  single  second  is  a  vast  interval  of 
time  in  the  atomic  universe,  during  which  the  atoms  have 
ample  time  to  carry  out  countless  billions  of  minute 
evolutions  ;  consequently  the  bright  flash  of  an  explosion 
is  to  an  atom  no  swift  change,  but  in  reality  betokens  the 
slow  and  orderly  passing  of  one  atomic  universe  into 
another. 

The  old  black  gunpowder  is  now  rapidly  passing  away, 
having  been  almost  entirely  superseded  by  other  explo- 
sives, as  we  shall  presently  see.  The  smoke  which  it  pro- 
duces when  fired  contains  more  than  50  per  cent,  of  the 
total  weight  of  the  powder,  and  is  thrown  out  as  solid 
matter  to  foul  the  atmosphere,  becloud  the  gunner,  and 
make  his  situation  a  conspicuous  target  for  the  enemy. 
The  modern  smokeless  powders  are  free  from  these 
defects. 

The  effects  producible  by  gunpowder,  mighty  as  they 
are,  fade  into  insignificance  when  compared  with  those 
producible  from  certain  modern  "  high  "  explosives  such 
as  dynamite  or  nitro-glycerine,  picric  acid,  and  mercury 
fulminate.  The  starting-point  in  the  manufacture  of 
dynamite  is  glycerine.  I  suppose  that  everyone  is 

1  Triumphs  and  Wonders  of  Modern  Chemistry,  2nd  ed.,  p.  6Q. 


THE    ROMANCE    OF    EXPLOSIVES  59 

acquainted  with  this  clear,  oily,  and  sweet-tasting  liquid, 
and,  indeed  many  of  us  have  eaten  it  in  honey,  for  it 
is  often  used  for  adulterating  this  article  by  unscrupulous 
dealers.  Glycerine  is  obtained  in  very  large  quantities  as 
a  secondary  product  in  the  manufacture  of  soap  and 
candles  from  oil  and  fats,  being  produced  by  the  action 
of  high-pressure  steam  or  boiling  alkalies  upon  these 
substances. 

In  order  to  make  nitro-glycerine,  the  glycerine  is 
sprayed  in  a  very  fine  stream  into  a  leaden  tank  (called  a 
"nitrator  ")  containing  strong  nitric  acid,  rendered  more 
active  by  being  mixed  with  sulphuric  acid,  and  kept  cold 
by  a  stream  of  cold  water  circulating  through  leaden  coils 
in  the  interior  of  the  vessel.  In  all  these  dangerous 
processes  stirring  is  required,  and  since  air  is  the  most 
easy  and  frictionless  means  of  agitating  a  liquid,  a  stream 
of  this  is  allowed  to  bubble  up  from  perforated  pipes 
placed  in  the  tank.  There  is  no  apparent  change,  for 
pure  nitro-glycerine  resembles  glycerine  itself  very  closely 
in  appearance  ;  nevertheless  the  following  change  has 
occurred  : 


C3H5(0  .  N02)3  +  3H20 

Glycerine          Nitric  acid  Nitro-glycerine  Water 

What  has  happened  is  that  three  hydrogen  atoms 
from  the  glycerine  molecule  have  been  displaced  by  the 
introduction  of  three  NO2  groups  from  the  nitric  acid. 
As  soon  as  the  chemical  change  is  ended  the  nitro- 
glycerine must  be  separated  from  the  nitric  acid  and  then 
washed  until  it  is  completely  free  from  adhering  acid. 
This  is  carried  out  as  follows.  The  leaden  tank  in  which 
the  reaction  takes  place  is  provided  with  a  narrow  conical 
top  as  seen  in  our  illustration  (Plate  1).  When  the  action 
is  over,  waste  acid  from  a  previous  charge  is  run  in  at  the 
bottom  and  displaces  the  nitro-glycerine  upwards,  and 


60      MODERN   CHEMISTRY   AND    ITS  WONDERS 

this  overflows  by  way  of  an  outlet  from  the  narrow  top 
of  the  nitrator.  This  top  chamber  is  a  closed  compart- 
ment with  a  glass  window  in  the  narrow  overflow  face. 
The  nitro-glycerine  containing  a  large  volume  of  water 
and  acid  runs  over  into  a  first  washing  vessel,  called  a 
"  forewash,"  seen  between  the  two  nitrators  in  Plate  1,  the 
flow  being  stopped  when  the  waste  acid  has  risen  to  the 
sight  window.  In  the  first  wash  tank  the  liquid  is  washed 
with  a  copious  supply  of  water  agitated  by  a  rapid  stream 
of  air  kept  bubbling  through  it  in  order  to  free  it  from 
acid.  The  water  is  skimmed  off  by  an  indiarubber  pipe, 
and  the  nitro-glycerine  is  then  run  into  a  second  vessel 
containing  a  large  volume  of  water,  seen  in  our  illustra- 
tion, Plate  1,  between  the  two  stairways,  and  is  then 
washed  again.  Next  it  runs  away  through  a  gutter  and 
enters  the  final  wash-house,  shown  in  Plate  2. 

In  this  the  heavy,  oily  nitro-glycerine  is  washed  with 
alkaline  water,  with  softened  warm  water,  and  with 
softened  cold  water,  and  finally  is  drained  off  and  collected. 
The  object  of  this  extremely  thorough  washing  is  to 
prevent  the  prepared  stuff  from  spontaneously  decom- 
posing in  use,  the  slightest  trace  of  acid  left  in  it  having 
been  known  to  cause  terrible  disasters  through  premature 
explosion.  The  nitro-glycerine  is  then  freed  from  moisture 
by  being  filtered  through  salt,  which,  being  unaffected  by 
the  explosive  liquid,  sucks  out  of  it  the  last  of  its  moisture, 
thus  serving  both  as  a  filter  and  a  dryer.  All  waste  water 
goes  to  a  large  tank  in  a  further  house,  and  is  run 
through  a  labyrinth  to  separate  any  nitro-glycerine  that 
it  still  contains.  The  mud  which  settles  in  the  tank  is 
run  with  the  waste  water  into  a  pond  at  some  distance, 
and  at  brief  intervals  a  cartridge  is  fired  in  the  bottom  of 
that  pond  in  order  to  blow  up  and  destroy  any  traces  of 
nitro-glycerine  which  may  accumulate  there. 

A  visit  to  a  large  explosive  works  is  well  worth  making. 


From  Cassier's  Magazine. 
Nitrators  Forewash  Nitrators 

PLATE  1.— Manufacture  of  Nitro-glycerine. 


From  Cassier's  Magazine. 
PLATE  2. — Interior  of  the  Washing  House  of  a  Nitro-glycerine  plant. 


THE    ROMANCE    OF    EXPLOSIVES  61 

The  most  elaborate  precautions  are  taken  to  avoid  disaster. 
The  buildings  are  separated  by  wide  intervals,  and  are 
buried  deep  in  the  earth  and  surrounded  by  great 
earthworks  in  order  to  minimise  the  effects  of  any  explo- 
sion. The  workmen  move  silently  about  clad  in  soft  felt 
shoes,  for  boots  containing  nails  might  cause  a  percussion 
and  result  in  a  terrible  disaster.  In  each  building  very 
few  men  are  employed,  so  that  any  culpable  carelessness 
on  the  part  of  a  workman  will  result  in  the  loss  of  only 
two  or  three  lives  at  most. 

In  one  room  you  will  see  the  dangerous  nitro-glycerine 
being  produced  by  the  hundredweight.  By  the  side  of 
the  tank  containing  the  nitric  and  sulphuric  acids,  into 
which  the  glycerine  is  steadily  pouring,  you  will  see  a 
workman  sitting  intently  watching  a  thermometer.  By 
him  is  an  apparatus  for  signalling  alarm  to  neighbouring 
buildings.  Anything  going  wrong  with  the  charge  in  the 
nitrator  will  manifest  itself  in  a  rapid  rise  of  temperature. 
The  utmost  upper  limit  of  temperature  allowable  is  25°  C. 
(77°  F.),  and  if  the  rise  continues  a  few  degrees  above 
this  the  whole  charge  may  explode  and  blow  the  whole 
building  into  the  air.  So  the  workman  sits  with  his  hand 
on  a  lever,  ready  in  an  instant,  by  means  of  a  single  move- 
ment of  it,  to  turn  off  the  stream  of  glycerine  and  dis- 
charge the  contents  of  the  nitrator  into  a  deep  tank  of  cold 
water,  situated  under  the  foundations  of  the  house.  Here 
it  is  flooded  and  all  danger  is  at  an  end. 

How  dangerous  is  the  operation  of  making  nitro- 
glycerine, and  how  easy  the  slightest  carelessness  of  the 
workmen  is  visited  by  the  supreme  penalty  of  death, 
may  be  seen  from  the  case  of  the  explosion  at  Hayle, 
which  occurred  on  January  5,  1904,  at  10.55  A.M.  At 
the  time  of  the  explosion  nitro-glycerine  was  flowing 
down  a  gutter  from  the  precipitating  house  to  the  washing- 
house,  which  were  separated  by  an  interval  of  about  a 


62     MODERN  CHEMISTRY  AND   ITS  WONDERS 

quarter  of  a  mile.  What  exactly  happened  will  now 
never  be  known,  but  it  is  believed  that  the  single  workman 
who  was  in  the  former  building  clumsily  dropped  the 
heavy  leaden  lid  of  one  of  the  tanks.  The  concussion 
was  sufficient  to  explode  the  whole  charge,  which  first 
blew  into  fragments  the  precipitating  house,  instantly 
killing  the  man,  and  then  flashing  down  the  gutter,  the 
explosion  entered  the  washing-house,  killing  the  three 
men  working  there,  and  hurling  the  building  into  the  air. 
The  thunder  of  the  explosion  was  heard  over  an  area  of 
3000  square  miles,  extending  even  so  far  as  Exeter,  some 
90  miles  away.  The  effects  of  the  explosion  were  visible 
for  several  miles  around  the  works,  chiefly  in  the  breakage 
of  glass.  Thus  at  St.  Ives,  no  less  than  four  miles  away, 
some  £200  worth  of  glass  windows  were  shattered,  many 
being  blown  entirely  out.  And  here  a  curious  thing  was 
noticed,  a  phenomenon  which  accompanies  most  terrific 
explosions.  The  windows,  especially  in  the  houses  facing 
the  works,  were  blown,  not  inwards  but  outwards.  The 
effect  of  an  explosion  at  a  distance  is  apparently  to  project 
the  atmosphere  vertically  and  produce  a  partial  vacuum 
around,  so  that  the  air  inside  a  vacuum-surrounded  house 
simply  bursts  it  open  and  blows  its  windows  outwards. 

But  this  reminds  me  of  the  exciting  time  which  a 
public  school  has  just  come  through  safely.  The  crisis 
came  suddenly  during  the  chemistry  lesson  of  one  of  the 
higher  classes. 

One  of  the  boys  quietly  remarked  to  the  master : 
"  Please,  sir,  I  have  made  a  pint  of  nitro-glycerine,"  and 
he  held  up  proudly  for  the  master  to  see  a  beaker  filled 
with  a  pale  yellow  liquid. 

The  class  stared  at  the  beaker  in  horrified  amazement. 
The  master  paled.  There  was  enough  of  the  deadly 
explosive  to  blow  the  whole  school  down,  and  half  the 
town  with  it.  "Good  God!"  said  the  master,  "  how  did 


THE    ROMANCE    OF    EXPLOSIVES  63 

you  make  it?"  "Oh/1  said  the  boy,  "I  just  poured 
a  pint  of  glycerine  into  a  mixture  of  strong  nitric  and 
sulphuric  acid."  The  master  carefully  approached  the 
beaker  and  gingerly  carried  it  to  a  cupboard.  Little 
work  was  done  during  the  rest  of  the  lesson.  Everyone 
walked  about  on  tip-toes,  and  none  ventured  near  the 
cupboard  where  the  terrible  jar  reposed.  After  the  lesson 
the  news  spread  like  wildfire.  Everyone  had  visions  of  the 
buildings  flying  skyward  like  a  fiery  rocket.  At  every  un- 
usual sound  boys  and  masters  jumped.  The  sudden  slam- 
ming of  a  door  sent  a  shudder  through  the  whole  school. 

Late  in  the  afternoon  the  chemistry  master  stole 
silently  from  the  school,  with  the  beaker  in  his  hand. 
Gingerly  he  picked  his  way  up  the  main-street  of  the 
town  in  a  zigzag  path  to  avoid  the  possibility  of  collision 
with  passers-by.  Arriving  at  the  playing  grounds,  he 
distributed  the  nitro-glycerine  in  remote  parts  of  the 
grounds.  When  he  returned  the  school  breathed  a  sigh 
of  relief,  and  set  up  the  master  as  a  lifelong  hero.  Mean- 
while the  enthusiastic  young  experimenter  was  sternly 
summoned  to  interview  the  infuriated  head  .  .  .  but  here 
we  will  stop.  Instead  of  dwelling  on  the  painful  scene  which 
ensued,  let  us  discuss  the  properties  of  nitro-glycerine. 

Nitro-glycerine  is  a  heavy,  colourless  oil  which,  like 
the  glycerine  from  which  it  is  derived,  tastes  sweet.  It 
is  very  poisonous  ;  in  large  quantities  it  acts  like  strychnine, 
and  causes  death  in  a  few  minutes  ;  but  in  small  quantities 
it  is  a  powerful  medicine  for  stimulating  the  heart.  It 
soaks  into  most  substances  in  a  most  extraordinary  manner. 
Indeed  if  placed  on  the  skin  it  will  soak  through  into  the 
blood,  causing  giddiness  and  severe  heart  trouble.  After 
a  time,  however,  workmen  get  used  to  it,  and  indeed 
actually  knead  the  glycerine  into  other  substances  by  the 
hand,  as  we  shall  presently  see. 

After  the  terrible  accidents  that    have  happened  the 


64     MODERN   CHEMISTRY  AND   ITS  WONDERS 

reader  will  be  surprised  to  hear  that  nitro-glycerine  does 
not  readily  explode.  It  is  not  nearly  so  explosive  as 
gunpowder.  In  fact  the  flame  of  a  match  can  be  quenched 
in  it  without  danger.  If  we  apply  a  light  to  it,  the  oil 
will  burn  quietly  with  a  smoky  flame.  If  poured  from 
an  open  vessel  on  to  a  fire  the  liquid  usually  blazes  up 
without  explosion.  In  fact  it  is  only  when  suddenly 
heated,  or  when  subjected  to  a  violent  shock,  such  as  that 
caused  by  the  explosion  of  a  small  charge  of  fulminating 
mercury,  that  it  will  explode.  But  when  the  substance 
does  explode  it  goes  off  with  terrific  violence,  shattering 
the  stoutest  structures  into  fragments.  Its  explosive  force 
is  estimated  at  eight  to  ten  times  that  of  the  same  weight 
of  gunpowder. 

Nitro-glycerine  has  several  properties  which  make  it 
dangerous  to  use  as  such.  For  example,  it  freezes  between 
4°  and  5°  C.  into  a  crystalline  solid  which  must  be  thawed 
again  before  using  by  placing  in  warm  water.  When 
solid  it  is  much  more  liable  to  explosion  by  simple  per- 
cussion than  when  liquid.  At  Hirschberg  a  mining 
overseer  was  killed  by  the  explosion  of  some  frozen 
nitro-glycerine  which  he  attempted  to  break  into  smaller 
pieces  with  a  pickaxe.  Like  water,  the  nitro-glycerine 
expands  in  freezing,  and  may  thus  burst  the  vessel  con- 
taining it  in  the  same  way  that  freezing  water  sometimes 
bursts  water-pipes.  Indeed  this  was  the  cause  of  a  terrible 
accident  some  years  ago.  A  box  of  nitro-glycerine  was 
being  sent  to  some  mines  and  was  lying  in  the  office  of 
a  luggage  company  waiting  to  be  fetched  away.  The 
cold  had  caused  the  substance  to  freeze  and  burst  its 
packing.  In  the  warm  office  it  again  melted  and,  unluckily 
for  him,  one  of  the  office  boys  observed  a  yellowish  liquid 
oozing  from  under  the  lid.  Being  of  an  industrious 
nature  he  at  once  fetched  a  hammer  and  nails  and 
began  to  fasten  the  lid  on  more  securely,  when,  with 


THE    ROMANCE    OF    EXPLOSIVES  65 

a  flash  like  lightning  and  a  roar  like  a  vast  thunder 
peal,  the  box  exploded,  shattering  the  whole  office  and 
causing  the  great  building  to  reel  and  almost  collapse. 
When  the  dust  of  fallen  masonry  and  the  smoke  had 
cleared  away,  the  horrified  searchers  discovered  that  some 
thirty  people  had  been  blown  to  pieces.  No  trace  of 
the  unfortunate  office  boy  was  ever  found  again.  This 
disaster  shows  that  nitro-glycerine  is  in  some  respects  very 
dangerous  to  store  and  to  transport.  Indeed  when  it 
first  began  to  be  manufactured  by  Mr.  Nobel — a  Swedish 
engineer — no  railway  or  ship  company  could  be  induced 
to  accept  the  danger  of  conveying  it.  Mr.  Nobel  was 
actually  on  the  point  of  abandoning  its  manufacture  when 
a  fortunate  accident  revealed  to  him  a  method  of  making 
it  transportable.  One  day  when  unloading  a  waggon 
containing  a  number  of  jars  of  nitro-glycerine  packed  in 
sand  to  prevent  breakage,  it  was  observed  that  a  jar  had 
fractured  and  that  the  nitro-glycerine  had  soaked  right 
into  the  sand,  just  as  ink  soaks  into  blotting  paper.  The 
sand  was  observed  to  have  the  same  powerful  explosive 
properties  as  the  pure  nitro-glycerine,  but  was  far  safer, 
and  being  in  a  compact  form,  far  easier  to  transport. 
The  old  "  Kieselguhr  Dynamite,"  in  fact,  is  merely  sand 
soaked  in  nitro-glycerine.  Ordinary  sand,  however,  is  not 
used  but  a  fine  sort  called  "  Kieselguhr,"  which  is  really 
nothing  else- than  the  skeletons  of  innumerable  myriads 
of  tiny  organisms,  and  will  absorb  no  less  than  three 
times  its  weight  of  nitro-glycerine.  The  quantity  absorbed, 
however,  must  be  always  less  than  the  capillarity  of  the 
cellular  diatoms  enables  them  easily  to  retain  without  drip 
or  overflow.  Kieselguhr  fully  charged  with  nitro-glycerine 
is  as  dangerous  as  the  unabsorbed  liquid  itself. 

Now  kieselguhr  (a  variety  of  sand)  is  in  itself  an  inert 
substance  and  so  reduces  the  effective  action  of  the  ex- 
plosive base  nitro-glycerine. 


66     MODERN    CHEMISTRY  AND   ITS  WONDERS 

A  great  advance  was  made  when,  instead  of  inert 
kieselguhr,  other  absorbants  for  the  nitro-glycerine  were 
used  which  are  themselves  explosives.  One  of  the  most 
powerful  explosives  in  use  is  of  this  nature  and  is  called 
"blasting  gelatine."  It  is,  in  effect,  a  solution  of  nitro- 
glycerine in  a  kind  of  gun-cotton  called  collodion  cotton 
(made  by  soaking  cotton  in  a  mixture  of  nitric  and 
sulphuric  acid).  It  is  made  by  mixing  together  7  to  10 
per  cent,  of  collodion  cotton  with  93-90  per  cent,  of 
liquid  nitro-glycerine  at  a  temperature  of  40°  C.  Solution 
takes  place  and  on  cooling  an  amber-coloured,  translucent, 
elastic  mass  is  produced.  When  saltpetre  and  wood  meal 
are  kneaded  into  the  mixture  we  get  the  explosive  known  as 
Gelatine  dynamite  or  gelignite.  These  dynamites  have  so  far 
displaced  the  old  "  kieselguhr  dynamite "  that  the  latter 
formed  in  1909  only  0'4  per  cent,  of  the  total  amount  of 
explosives  used  in  mines  and  explosives  in  Great  Britain. 

And  now  a  few  words  on  what  dynamite  has  done  for 
civilisation.  Modern  times  have  been  distinguished  by 
the  carrying  through  of  gigantic  engineering. operations  ; 
it  is  quite  safe  to  say  that  without  the  employment  of 
high  explosives  these  could  never  have  been  achieved. 
Tunnelling  operations  have  become  quite  simple,  dynamite 
cartridges  enabling  men  to  blast  their  way  right  through 
the  hearts  of  mountains,  while  dynamite  makes  the  con- 
struction of  great  canals  an  easy  matter  ;  the  rocks  and 
earth  in  the  way  are  simply  shattered  by  dynamite  ex- 
plosions and  the  debris  is  then  carted  away  by  mechani- 
cal appliances.  Consequently  once  any  great  engineering 
feat — such  for  example  as  the  making  of  the  Panama 
Canal — is  decided  upon,  the  price  of  dynamite  and  the 
raw  product  glycerine  from  which  it  is  obtained  at  once 
goes  up  with  a  bound,  as  the  demand  for  explosives  exceeds 
the  supply. 

Now  these  great  engineering  operations  have  all  one 


THE    ROMANCE    OF    EXPLOSIVES  67 

object  in  view,  and  that  is  the  speeding  up  of  communica- 
tion between  one  part  of  the  world  and  another  ;  and  so 
dynamite,  perhaps  more  than  any  other  agent,  has  knit  the 
world  into  a  closely  connected  civilised  whole.  Methods 
of  quick  transit  of  persons,  inventions,  news,  and  mer- 
chandise from  one  part  of  the  world  to  another  have 
done  more  to  bring  universal  peace  and  prosperity  into 
the  world  than  any  other  influence,  and  as  this  has  in 
the  main  been  made  possible  by  engineers  who  in  their 
turn  could  only  do  their  work  by  using  high  explosives, 
the  inventor  of  dynamite  probably  has  been  one  of  the 
greatest  benefactors  to  humanity. 

Thousands  of  tons  of  dynamite  are  made  yearly  and 
used  for  blasting  purposes.  In  using  gunpowder  for 
blasting  it  is  necessary  tightly  to  confine  it,  by  what  is 
called  "  tamping,"  in  a  hole  prepared  for  it  in  the  rock. 
In  fact  if  gunpowder  was  exploded  on  an  iron  plate  in 
the  open  air  the  disruptive  effect  would  be  nil.  It  must 
be  confined.  But  this  is  not  so  with  dynamite  or  nitro- 
glycerine. They  exert  their  greatest  force  in  the  direction 
of  those  points  in  actual  contact  with  them.  Hence  if 
a  small  amount  of  dynamite  be  merely  placed  on  the  top 
of  a  large  boulder  rock  or  on  an  iron  plate,  and  be 
absolutely  unconfined  in  any  way,  then  on  exploding  the 
dynamite  the  rock  or  plate  will  be  shattered  into  a  thousand 
fragments.  Hence  dynamite,  made  up  into  small  tin 
cartridges  for  convenience,  is  merely  placed  in  the  drill 
holes  without  tamping  of  any  kind.  Sometimes  the  liquid 
nitro-glycerine  itself  has  been  poured  into  the  hole  and 
then  a  little  water  poured  on  top  is  the  only  means  used 
to  confine  it. 

This  makes  nitro-glycerine  rather  a  favourite  explosive 
for  burglars  who  wish  to  blow  open  safes.  This  is 
especially  the  case  in  America.  The  thieves,  after  forcing 
their  way  into  a  safe  room,  next  lute  up  all  the  crevices 


68     MODERN   CHEMISTRY  AND   ITS  WONDERS 

between  the  door  and  the  walls  of  the  safe  by  soap  or 
some  similar  lute.  Then  they  pour  the  liquid  nitro- 
glycerine in  through  cracks  in  the  safe  door.  A  detonator 
is  then  applied  and  the  explosion  usually  succeeds  in 
detaching  the  safe  door  from  the  walls,  thus  making  the 
contents  accessible  to  the  criminals. 

In  a  recent  burglary  at  the  London  Hippodrome  a 
gang  of  thieves,  who  had  secreted  themselves  in  the 
building  after  the  performance,  attacked  the  night- 
watchman  and  after  gagging  and  chloroforming  him, 
proceeded  to  an  underground  room  known  as  the  treasury 
and  blew  open  the  safe  with  gelignite.  This  is  the 
account  of  the  night-watchman: — "  About  1.30  at  night, 
while  patrolling  the  theatre,  I  came  to  the  vestibule  at 
the  main  entrance.  I  was  carrying  a  bull's  eye  lantern, 
and  there  was  a  little  light  coming  through  the  glass 
doors  from  the  street.  Suddenly  two  men  sprang  at  me 
and  threw  me  down.  One  man  pinned  me  down  while 
the  other  pressed  a  cloth  over  my  face.  There  was  a 
strong  odour  of  chloroform,  and  while  I  was  struggling 
to  free  myself  I  lost  consciousness. 

"  It  was  about  5.30  A.M.  when  I  awoke.  My  head  was 
aching  badly  and  I  felt  very  drowsy.  My  lamp  was  by 
my  side  but  it  had  gone  out.  I  at  once  thought  about 
the  safe,  and  getting  up  I  ran  to  the  door  leading  to  the 
underground  treasury  room.  It  was  open.  I  ran  down- 
stairs and  saw  the  safe,  which  weighed  over  a  ton,  lying 
on  its  back.  Its  door,  which  had  been  forced,  was  all 
buckled  up  as  if  made  of  tin.  All  the  money  (some  £500 
or  so)  which  was  kept  in  the  safe  was  gone.  I  at  once 
called  in  the  police."  The  police  soon  found  that  the 
burglars  had  turned  over  the  safe,  drilled  some  holes  in 
the  cracks  of  the  door,  and  then  forced  in  a  quantity  of 
gelignite  (which  as  put  up  in  cartridges  has  a  creamy 
consistency).  All  crevices  between  the  walls  and  the 


THE    ROMANCE    OF    EXPLOSIVES  69 

door  were  then  sealed  up  by  yellow  soap,  and  the  charge 
was  exploded  by  a  time-fuse  inserted  in  the  keyhole. 
The  explosion  would  not  make  much  more  noise  than 
the  discharge  of  a  rifle,  and  so  was  not  heard  in  the 
street 

As  an  agent  used  for  blasting  nitro-glycerine  is  so 
vastly  superior  to  gunpowder  that  it  must  be  regarded  as 
one  of  the  most  valuable  discoveries  of  our  age.  Yet  it 
has  no  value  whatever  as  a  projective  agent.  Exploded 
in  the  chamber  of  a  gun  it  shatters  it  to  pieces. 
Now  what  is  the  cause  of  the  singular  difference  in  the 
explosive  effect  of  dynamite  and  gunpowder  ?  The 
reason  is  this :  in  gunpowder  the  act  of  explosion  con- 
sists mainly  in  the  union  of  carbon  and  oxygen  to  produce 
gaseous  products.  But  the  carbon  and  oxygen  atoms  are 
in  different  molecules.  The  grains  of  charcoal  and  nitrate, 
although  very  small,  have  a  sensible  magnitude,  and  con- 
sist each  of  many  million  molecules.  Now  the  chemical 
union  of  fhe  carbon  atoms  of  the  charcoal  with  the 
oxygen  of  the  nitrate  can  only  take  place  on  the  surface 
of  the  grains.  The  first  layer  of  molecules  must  be  con- 
sumed before  the  second  can  be  reached,  and  so  on. 
Hence  the  process,  although  very  rapid,  must  take  an 
appreciable  time. 

In  the  case  of  nitro-glycerine  and  dynamite,  however, 
the  carbon  and  oxygen  atoms  are  in  the  same  molecule  at 
an  almost  infinitesimal  distance  apart.  Hence  the  com- 
bustion takes  place  in  the  molecules  themselves  and  is  prac- 
tically instantaneous  ;  thus : 

4CaH6(O.N01)s=      12CO?     +10H20+    6N2    +    O2 

Nitro-glycerine          Carbon  dioxide  Water         Nitrogen       Oxygen 

When  the  substance  explodes  the  oxygen  atoms  at- 
tached to  the  nitrogen  rush  for  the  carbon  and  hydrogen 
atoms  and  unite  with  them  to  form  carbon  dioxide  and 


70     MODERN   CHEMISTRY   AND   ITS  WONDERS 

steam,  while  the  nitrogen  atoms  are  set  free  and  part  of 
the  oxygen  as  well.  The  whole  molecule  is  thus  suddenly 
shattered  and  flies  apart  into  gaseous  products  which 
occupy  more  than  1200  times  the  volume  of  the  original 
nitro-glycerine,  if  the  gaseous  volume  is  calculated  at  ordi- 
nary temperatures  and  pressures ;  but  the  heat  liberated 
expands  the  gas  to  nearly  eight  times  this  volume.  And 
all  this  takes  place  almost  simultaneously  among  all  the 
vast  assemblance  of  nitro-glycerine  molecules.  So  that 
the  gas  is  liberated  practically  instantly. 

Now  all  our  experiments  are  made  in  air,  and  this  air 
presses  with  an  enormous  weight  on  every  surface.  Each 
square  yard  of  surface  supports  about  nine  tons  weight. 
Hence  if  a  volume  of  gas  is  suddenly  liberated  it  must 
press  back  this  weight  of  air  in  order  to  find  room  for 
itself.  In  the  case  of  gunpowder  the  300  volumes  of  gas 
come  off  slowly  enough  to  lift  and  displace  the  air  without 
getting  much  compressed.  In  the  case  of  nitro-glycerine, 
however,  the  1200  volumes  of  gas  come  off  instantly  and 
cannot  lift  the  air  suddenly  enough  to  relieve  the  pressure. 
Hence  an  enormous  gaseous  pressure  is  suddenly  de- 
veloped around  the  explosive,  which  shatters  the  material 
in  contact  with  it.  The  following  illustration  may  help 
the  reader  to  realise  this  more  clearly.  Take  a  light  wooden 
surface,  say  one  yard  square.  Move  it  slowly  through  the 
atmosphere  and  we  encounter  little  resistance  because  the 
air  flows  round  it  as  it  moves.  If,  however,  we  force  it 
rapidly  forward  the  resistance  greatly  increases  since  the 
air  has  no  time  to  flow  round  it.  If  we  increase  the 
velocity  of  the  motion  to  that  of  an  express  train — a  mile 
a  minute — we  would  encounter  a  resistance  which  no 
human  strength  could  overcome.  Increase  this  velocity 
a  dozen  times,  that  is  to  say  make  it  move  as  rapidly  as 
sound  waves,  and  the  air  would  oppose  such  a  resistance 
that  our  wooden  board  would  be  shivered  into  splinters. 


THE    ROMANCE    OF    EXPLOSIVES  71 

Multiply  this  velocity  ten  times  and  not  even  a  boiler 
plate  could  withstand  the  resistance.  Multiply  the  velocity 
once  more  by  ten  and  we  reach  the  speed  with  which  the 
earth  rushes  round  its  orbit,  about  twenty  miles  a  second. 
To  a  body  moving  with  such  a  vast  velocity  the  air  at  the 
surface  of  the  earth  presents  an  almost  impenetrable 
barrier  against  which  the  strongest  rocks  may  be  dashed 
to  pieces.  Indeed  this  effect  often  occurs  when  meteorites 
rush  into  our  atmosphere  with  planetary  velocities.  They 
are  often  shattered  with  a  loud  explosion. 

Now  in  the  case  of  a  piece  of  dynamite  placed  on  an 
open  rock  or  iron  plate  and  caused  to  explode,  we  get  a 
volume  of  gas  some  thousands  of  times  greater  than  the 
volume  of  the  dynamite  suddenly  shooting  forth  with  a 
velocity  of  many  miles  a  second.  It  encounters  in  an 
instant  an  enormous  resistance  from  the  air,  and  so  a 
sudden  gaseous  pressure  of  some  thousands  of  tons  is 
generated  all  round  the  dynamite  ;  and  this  instantaneous 
pressure  has  all  the  effect  of  a  tremendous  blow  on  the 
material  on  which  the  explosive  is  placed.  Hence  it  is 
easy  to  understand  why  the  strongest  rocks  and  the  most 
impenetrable  of  iron  plates  are  shivered  into  splinters  by 
the  force  of  its  explosion  in  the  open  air  alone.  In  the 
case  of  gunpowder  the  gas  is  liberated  fairly  slowly,  and 
consequently  such  an  enormous  pressure  against  the  air  is 
never  generated.  So  that  gunpowder  placed  on  an  open 
surface  in  air  and  exploded  exerts  no  disruptive  effect. 
It  is  only  when  its  gases  are  liberated  in  a  confined  space 
that  the  pressure  becomes  great  enough  to  shatter  massive 
structures. 

The  reader  will  doubtless  consider  that  such  an 
enormously  swift  rush  of  gas  as  that  which  causes  a 
dynamite  explosion  must  be  quite  exceptional  in  the 
scale  of  nature.  Certainly,  on  the  earth  gases  seldom 
rush  so  rapidly.  Even  in  the  mightiest  storms  the  wind 


72      MODERN  CHEMISTRY  AND    ITS  WONDERS 

seldom  travels  more  than  40  yards  a  second,  whereas 
the  gas  rushing  from  dynamite  has  a  velocity  of  many 
miles  a  second  !  but  we  must  remember  that  anything 
which  is  abnormal  on  the  earth  may  be  a  normal  condition 
in  other  parts  of  the  universe.  And  so  it  is  in  this  case.  In 
myriads  of  the  suns  scattered  through  space  the  stupen- 
dous gaseous  velocity  which  causes  a  dynamite  explosion 
is  vastly  exceeded  by  that  of  currents  of  gas  in  their 
atmospheres.  On  the  sun,  for  example,  mighty  winds 
of  white  hot  gas  rush  along  with  velocities  of  700  to  800 
miles  a  second.  The  pressure  and  tearing  force  of  such 
winds  must  exceed  a  million-fold  the  most  terrific  dyna- 
mite explosion  producible  by  us.  So  that  over  the  whole 
vast  surface  of  the  sun  there  is  continually  going  on  age 
after  age,  as  a  normal  condition,  the  same  vast  explosive 
action  which  we  see  reigning  for  a  fraction  of  a  second 
when  a  dynamite  bomb  explodes  1 

The  next  explosive  that  we  will  deal  with  is  gun- 
cotton.  This  has  a  chemical  composition  somewhat 
similar  to  iiitro-glycerine  and  is  produced  by  the  action  of 
nitric  acid  on  cotton.  Pure  cotton  which  has  been  freed 
from  fat  and  grease  by  boiling  with  alkali  is  immersed  in 
a  mixture  of  concentrated  nitric  and  sulphuric  acids  (1:  3) 
for  five  or  six  minutes.  The  cotton  is  removed  and 
the  excess  of  acids  squeezed  out.  It  is  next  placed  in 
cooled  earthenware  pots  for  24  hours  until  the  process 
of  nitration  is  completed.  The  cotton  must  then  be  most 
thoroughly  washed  in  order  to  remove  from  it  every 
trace  of  acid.  If  this  is  not  done  a  disastrous  explosion 
may  result  at  a  later  stage  owing  to  the  spontaneous  de- 
composition of  the  product. 

In  order  to  carry  out  the  washing,  the  cotton  is  first 
placed  in  a  centrifugal  machine,  and  the  greater  part  of 
the  acid  is  there  wrung  out  from  it.  Then  it  is  plunged 
into  a  tank  containing  a  large  volume  of  rapidly  chang- 


From  Gassier' s  Magazine, 
PLATE  3. — Shaping  charges  of  gun-cotton  with  a  band  saw. 


From  Gassier  s  Magazine. 
PLATE  4. — Chiselling  and  turning  blocks  of  gun-cotton  for  charging  shells. 

The  brass-nose  shell  is  shown  on  the  right-hand  stool,  and  the  charge  for  this  on 
the  left-hand  stool  and  in  the  lathe. 


THE    ROMANCE    OF    EXPLOSIVES  73 

ing  water  in  which  the  gun-cotton  is  kept  in  agitation  by 
a  revolving  feathered  wheel.  Afterwards  it  is  boiled  with 
water  which  usually  contains  a  small  quantity  of  sodium 
carbonate.  The  physical  character  of  the  cotton  fibre 
is  such  that  it  presents  every  obstacle  to  the  removal  of 
the  free  acid,  since  it  is  built  up  of  capillaries,  but  by 
reducing  these  tubes  to  the  shortest  possible  length  the 
removal  of  the  acid  from  their  interiors  is  much  facilitated. 
The  material  is  therefore  placed  for  several  hours  in  a 
paper-pulper  or  rag-engine.  There  it  is  passed  con- 
tinuously around  under  the  beater  knives  until  it  is 
chopped  into  a  condition  of  complete  division  exactly 
like  paper  pulp  or  corn  meal.  The  pulp  is  then  pumped 
into  other  vessels  and  again  washed  and  boiled  with  water 
until  no  trace  of  acid  can  be  detected  by  delicate  chemical 
tests  in  the  wash-water.  Gun-cotton  before  pulping  and 
when  dry  looks  exactly  like  the  cotton  from  which  it  was 
made  but  has  a  somewhat  harsher  feel. 

To  prepare  the  pulp  for  use  in  filling  torpedoes  or 
shells,  the  pulp  from  the  rag  machine  is  conveyed  to  a 
moulding  press  and  the  moulded  discs  or  blocks  are 
taken  to  a  final  hydraulic  press  ;  here  they  are  fashioned 
into  the  desired  form,  just  as  papier  mache  is.  As  taken 
from  the  press  these  blocks  contain  12  to  16  per  cent, 
of  water,  but  as  sent  into  service  they  contain  about 
35  per  cent.,  which  is  added  by  allowing  the  com- 
pressed blocks  to  soak  in  a  trough  of  fresh  water  until 
they  cease  to  absorb  more.  If,  in  providing  charges  for 
torpedoes  and  shells,  it  is  inconvenient  to  mould  the 
portions  for  the  heads  and  other  parts,  these  are  readily 
and  without  much  danger  shaped  from  blocks  by  cutting 
them  with  a  chisel  or  band  saw,  or  boring  with  a  drill,  or 
turning  in  a  lathe,  being  careful  to  keep  a  stream  of 
water  flowing  on  the  gun-cotton  during  the  operation. 
(See  Plates  3  and  4.) 


74     MODERN  CHEMISTRY   AND   ITS  WONDERS 

Gun-cotton  does  not  readily  explode.  If  a  match  is 
applied  to  it  when  unconfined  it  merely  flashes  away 
in  a  whiff  of  flame.  Wet  gun-cotton  will  not  burn  at  all, 
and  bullets  may  be  fired  into  bales  of  the  stuff  without 
any  bad  effects.  When  dry,  however,  a  sharp  blow  has 
been  known  to  cause  explosion. 

Consequently  it  is  in  the  drying  houses  that  explosions 
of  gun-cotton  usually  occur.  Indeed  after  scores  of  years 
of  manufacture  all  danger  is  not  eliminated,  and  quite  a 
bad  explosion  occurred  so  recently  as  Monday,  March  3rd 
1913,  at  Nobel's  explosive  works  in  Ayrshire,  whereby 
seven  men  were  killed  outright  and  ten  seriously  injured. 

Apparently  decomposition  occurred  among  boxes  of 
gun-cotton  drying  in  the  heating  room,  and  so  violent  was 
the  concussion  that  in  a  village  half  a  mile  away  the  roofs 
of  houses  cracked  and  came  crashing  down  upon  their 
occupants,  while  chimney  stacks  were  thrown  down  in  all 
directions,  buildings  rocking  as  if  smitten  by  an  earth- 
quake. At  Glasgow,  fully  thirty  miles  away,  windows 
rattled  in  a  violent  manner  and  crockery  fell  down  from 
shelves  and  was  broken.  This  occurred  in  a  most  scien- 
tifically managed  works  where  every  precaution  was  taken 
for  isolation  of  the  explosive  and  safety  of  the  workers. 
In  fact  this  disaster  shows  that  those  who  have  in  harness 
great  atomic  forces  always  stand  in  danger  of  losing  con- 
trol of  them.  Like  fire,  modern  explosives  are  excellent 
servants  but  very  bad  masters. 

In  practice  gun-cotton  is  always  set  off  by  means  of 
a  detonator  charge,  which  is  exploded  in  the  middle  of  it 
and  thereby  gives  such  a  shock  to  the  chemical  molecular 
structure  that  the  whole  mass  instantly  explodes  with 
terrific  force,  much  in  the  same  way  that  dynamite  does. 
Indeed  the  tearing  effect  is  much  the  same  in  both  cases. 

The  chemical  constitution  of  this  highly  explosive 
gun-cotton  as  used  in  mines,  torpedoes  and  shells  is 


THE    ROMANCE    OF    EXPLOSIVES  75 


Js,  being  produced  from  cellulose  (of  which 
cotton  fibre  is  made  up),  which  has  the  formula  [CgH^OJ^ 
as  the  result  of  the  replacement  of  three  hydrogen  atoms 
in  the  cellulose  molecule  by  three  nitro  groups,  NO2,  from 
the  nitric  acid.  "  Trinitro-cellulose,"  as  the  substance 
is  called  chemically,  is  insoluble  in  ether  but  soluble  in 
acetone.  There  exist,  however,  lower  forms  of  gun-cotton, 
in  which  only  one  or  two  nitro  groups  have  entered  into 
the  cellulose  molecule,  and  these  are  soluble  in  ether, 
their  ethereal  solution  being  known  as  collodion  ;  they 
form  the  basis  of  what  is  known  as  celluloid. 

Powders  are  now  made  of  "  gelatinised  "  gun-cotton, 
i.e.  gun-cotton  which  by  means  of  partial  solution  and 
subsequent  evaporation  of  the  solvent  is  made  into  a  stiff 
jelly-like  elastic  mass.  One  powder  of  this  sort,  which 
has  caused  much  discussion  recently,  is  the  French  "  B 
Powder."  It  is  a  smokeless  powder  consisting  of  two 
parts  of  insoluble  nitro-cellulose  (i.e.  gun-cotton)  mixed 
with  one  part  of  soluble  nitro-cellulose  (i.e.  collodion 
wool),  the  whole  made  into  a  jelly  by  adding  a  mixture 
of  alcohol  and  ether  and  stirring  until  the  ingredients 
form  a  "  jelly,"  after  which  the  alcohol  and  ether  are  eva- 
porated. 

Such  powders  formed  of  "  gelatinised  "  nitro-cellulose 
or  gun-cotton  are  for  some  unknown  reason  much  more 
unstable  than  the  ungelatinised  parent  substances,  al- 
though apparently  the  process  of  gelatinisation  is  a 
merely  physical  one  attended  by  no  chemical  change. 
When  kept  for  some  years  such  powders  often  gradually 
decompose  with  increasing  rise  of  temperature,  and  then 
suddenly  the  decomposition  becomes  so  marked  and  the 
rise  of  temperature  so  great  that  the  mass  may  explode 
with  great  violence.  Consequently  the  French  naval 
authorities  have  decreed  that  all  B  Powder  over  four 
years  old  shall  be  destroyed  by  being  sunk  in  the  sea. 


76     MODERN    CHEMISTRY  AND    ITS  WONDERS 

This  discovery  was  only  made  at  the  cost  of  human  life, 
owing  to  a  terrible  series  of  disasters  to  French  battle- 
ships. 

First  of  all  the  French  battleship  Jena  blew  up  with  a 
terrible  loss  of  life,  to  be  followed  very  shortly  by  a  still 
more  appalling  disaster.  On  Monday,  September  23rd 
1911,  at  5.35  in  the  morning  an  unexpected  explosion 
took  place  on  the  battleship  Liberte  lying  at  anchor  in 
Toulon  harbour.  As  the  alarmed  men  swarmed  up  from 
below,  this  explosion  was  followed  by  a  series  of  others 
of  fearful  violence,  culminating  in  a  terrific  explosion 
at  5.55  A.M.,  which  could  be  heard  thirty  miles  away. 
The  air  around  was  filled  with  debris,  a  captain  on  a 
training  ship  two  miles  away  being  killed  by  a  flying 
fragment,  while  great  chunks  of  massive  iron  armour, 
weighing  tons,  were  hurled  in  all  directions  around  the 
ill-fated  vessel,  crashing  through  the  sides  and  decks  of 
neighbouring  warships  and  killing  and  wounding  men  in 
all  directions.  In  a  few  minutes  no  less  than  200  lives 
were  lost  and  the  noble  vessel  was  reduced  to  a  mass  of 
twisted  and  torn  scrap  metal.  Our  illustration  shows  the 
battleship  Liberte  after  the  explosion  (Plate  5). 

Cordite  is  a  mixture  of  nitro-glycerme,  gun-cotton,  and 
vaseline  in  the  proportions  :  nitro-glycerine,  30  parts,  gun- 
cotton,  65  parts,  and  vaseline,  5  parts.  The  combustion 
of  the  powder  without  vaseline  causes  excessive  friction  of 
the  projectile  in  the  gun,  producing  rapid  wearing  of  the 
rifling  ;  it  is  chiefly  to  overcome  this  that  the  vaseline  is 
introduced,  for  on  explosion  a  thin  film  of  greasy  matter 
is  deposited  in  the  gun,  and  acts  as  a  lubricant.  In  order 
to  prepare  this  substance  the  nitro-glycerine  is  poured 
over  the  gun-cotton  and  well  mixed  by  hand  ;  then 
acetone  is  added  and  the  whole  mingled  in  a  knead- 
ing machine  for  3J  hours.  The  acetone  does  not  enter 
into  the  constitution  of  the  powder,  but  since  it  dis- 


THE    ROMANCE    OF    EXPLOSIVES  77 

solves  both  the  nitro-glycerine  and  the  gun-cotton  it 
allows  them  to  be  thoroughly  mixed  and  incorporated 
into  a  homogeneous  mass.  The  acetone  is  afterwards 
removed  during  the  drying  process.  Vaseline  is  now 
added  and  the  kneading  is  continued  for  some  hours. 
The  cordite  paste  is  first  subjected  to  a  preliminary 
pressing,  and  is  finally  forced  through  a  hole  of  the 
proper  size  in  a  plate  by  hydraulic  pressure  or  by  hand. 
The  thick  fibrous  paste,  if  of  a  small  diameter,  is  wound 
on  drums,  whilst  if  of  a  large  diameter,  it  is  cut  off  in 
suitable  lengths.  The  most  tedious  process  is  the  drying 
out  of  the  solvent  acetone.  If  the  drying  is  done  quickly, 
the  surface  of  the  cords  is  hardened,  and  the  solvent 
cannot  escape  from  the  interior.  Large  cordite  may  thus 
require  as  many  as  seventy  days  in  which  to  dry  com- 
pletely. This  drying  is  effected  in  steam-heated  stoves,  and 
the  drying  of  the  exterior  surface  must  proceed  only  as 
quickly  as  the  interior  will  give  up  its  solvent  to  the  more 
outward  portions.  It  is  for  this  reason,  among  others, 
that  a  large  store  of  cordite  is  necessary  to  meet  possible 
demands,  because  the  substance  cannot  be  made  in  a  day 
or  a  week,  and  any  hurry  in  drying  would  cause  the  rods 
to  split  and  alter  their  rate  of  burning  and  so  spoil  their 
ballistic  properties.  Cordite  is  a  splendid  ammunition  for 
guns,  and  forms  the  basis  of  what  is  now  known  as  smoke- 
less powder.  It  is  perfectly  safe,  a  rifle  bullet  fired  into  a 
mass  of  it  only  causing  it  to  burn  quietly,  while  a  detonator 
cannot  be  made  to  explode  it.  Balliste  consists  of  nitro- 
glycerine 37*5  per  cent,  and  nitro-cotton  62*5  per  cent.  -I 
It  is  impossible  in  the  course  of  an  article  such 
as  the  present  to  pass  in  review  all  the  numerous  ex- 
plosives that  are  known.1  We  should  however  mention 
Picric  Acid,  C6H2(NO2)3OH,  which  is  prepared  by  dis- 

1  For  further  details  the  reader  should  consult  the  author's  book,  Industrial 
Chemistry,  vol.  i.,  "  Organic,"  where  a  full  account  of  the  subject  is  given. 


78     MODERN   CHEMISTRY  AND   ITS  WONDERS 

solving  phenol,  CgH5OH  (carbolic  acid),  in  nitric  acid.  It 
or  its  salts  are  used  for  shells  under  the  names  "  Lyddite," 
"  Mellinite,"  &c.  Trinitrotoluene,  CgH2(NO2)3CH3,  is  now 
very  largely  used  and  is  stated  to  be  superseding  picric 
acid. 

Picric  acid  assumes  the  form  of  a  crystalline  solid, 
composed  of  a  mass  of  very  beautiful  bright  yellow  plates 
or  prisms.  In  fact  it  was  (and  still  is  to  some  extent) 
used  as  a  yellow  dye. 

Picric  acid  under  ordinary  circumstances  is  quite  safe 
to  make.  In  fact,  students  in  chemical  laboratories  are 
allowed  to  make  the  substance  as  an  exercise  ;  it  can  be 
melted  without  danger,  and  even  be  allowed  to  burn 
without  explosion.  Although  so  safe  under  ordinary 
circumstances,  yet  when  exploded  with  a  mercury  ful- 
minate detonator  it  goes  off  with  fearful  violence,  being 
even  more  powerful  than  gun-cotton  or  dynamite. 

When  picric  acid  explodes  it  belches  forth  extremely 
poisonous  gases.  Among  these  we  may  mention  the 
suffocating  carbon  dioxide  and  nitrogen,  the  blood- 
poisoning  carbon  monoxide  and  nitrogen  oxides,  the 
latter  of  which  when  breathed  causes  pneumonia  and  a 
suffocating  death,  while  the  former  is  the  active  agent  of 
gas  poisoning  in  mine  explosions  ;  last  but  not  least  there 
are  evolved  vapours  of  the  deadliest  of  all  poisons — 
namely,  prussic  or  hydrocyanic  acid  (p.  48) — a  single 
breath  of  which  can  kill  a  man  with  the  suddenness  of 
the  knife.  In  addition  to  this,  the  intense  heat  of  an 
exploding  shell  converts  part  of  the  picric  acid  charge 
into  very  bitter  and  irritating  vapours,  which  dye  all 
objects  in  the  immediate  neighbourhood  a  deep  yellow 
colour. 

We  can,  therefore,  readily  imagine  the  really  terrible 
effects  produced  by  the  explosion  of  great  shells  weighing 
nearly  a  ton,  especially  if  the  explosion  takes  place  in  a 


THE    ROMANCE    OF    EXPLOSIVES  79 

somewhat  confined  space,  such  as  the  hold  of  a  battleship. 
First  there  is  the  terrific  thunder  and  blaze  of  light  of  the 
explosion  itself ;  then  comes  a  sudden  increase  of  air 
pressure,  and  the  men  not  annihilated  by  the  explosion 
itself  are  hurled  in  all  directions  ;  lastly  come  torrents 
of  intensely  poisonous  gases  evolved  as  a  result  of  the 
decomposition  of  the  picric  acid.  Men  gasp  and  die 
suddenly,  killed  by  the  prussic  acid  and  nitrogenous 
fumes.  Such  men  will  appear  black  and  livid  in  the  face, 
and  are  often  stained  yellow  by  vapours  from  unexploded 
picric  acid. 

In  fact  by  the  aid  of  the  enormous  guns  constructed 
by  modern  science  the  very  strongest  land  fortifications 
can  be  reduced  to  ruin  in  a  few  hours.  We  are  told, 
for  example,  that  some  of  the  Antwerp  forts  were  literally 
blown  into  the  air  by  shell  fire,  so  that  what  was  once  a 
fort  was  transformed  into  a  deep  cavity. 

The  great  15-inch  shells  of  the  English  Navy  hit 
with  precision  at  12  miles  and  pound  to  dust  everything 
within  a  hundred  yards,  while  ranks  of  men  are  hurled 
down  by  such  shells  when  more  than  a  quarter  of  a  mile 
from  the  place  whereon  the  projectile  falls. 

Byron's  words,  written  over  a  hundred  years  ago  : — 

"  The  armaments  that  thunderstrike  the  walls 
Of  rock-built  cities,  making  nations  quake 
And  Monarchs  tremble  in  their  capitals." 

seem  almost  literally  descriptive  of  the  overwhelming 
nature  of  modern  shell  fire  when  directed  on  fixed  land 
forts. 

Picric  acid  for  military  purposes  is  usually  fused  and 
poured  while  in  a  molten  condition  into  the  shell.  The 
disadvantage  of  its  use,  however,  is  that  it  is  an  acid,  and 
so  combines  with  metals  to  form  salts  called  "  picrates," 
some  of  which  are  very  explosive  and  unstable  bodies. 


8o     MODERN   CHEMISTRY  AND   ITS   WONDERS 

There  is,  therefore,  always  the  danger  that  the  metal 
forming  the  shell  and  the  picric  acid  charge  inside  may 
unite  to  form  some  of  these  unstable  explosives,  and  so 
cause  a  disastrous  premature  explosion. 

For  these  reasons  another  nitro-derivative,  viz., — 
Trinitrotoluene ,  C6H2(NO2)3CH3,  has  recently  come  into 
extended  use,  although  it  is  not  quite  such  a  powerful 
explosive  as  picric  acid.  It  is  made  by  treating  toluene 
(which  is  contained  in  coal  tar)  with  nitric  and  sulphuric 
acid.  It  crystallises  in  yellow  masses,  and  is  really  an 
extraordinarily  safe  explosive. 

For  example,  it  can  be  burnt,  hit  with  a  hammer, 
bullets  can  be  fired  through  it,  and  all  sorts  of  other 
rough  mechanical  treatment  meted  out  to  it  without 
causing  it  to  explode. 

As  much  as  one  ton  weight  of  the  substance  has 
been  known  to  burn  away  quietly  without  explosion. 
Moreover,  it  has  no  acid  properties,  and  so  it  will  not 
(like  picric  acid)  combine  with  metals  to  form  unstable 
explosive  compounds.  By  means  of  a  detonator  of 
mercury  fulminate  it  can  be  caused  to  explode  with  very 
great  violence — although  not  so  violently  as  wet  gun- 
cotton.  The  fragments  of  shells  filled  with  this  substance 
are  large  enough  to  do  much  damage  at  a  considerable 
distance,  whereas  picric  acid  and  gun-cotton  tend  to 
pulverise  shells  and  so  localise  their  effect. 

One  curious  effect  of  the  outbreak  of  war,  therefore, 
is  to  make  supplies  of  a  number  of  products  derived  from 
coal  tar  of  great  military  importance.  Thus  coal  tar 
contains  both  phenol  and  toluene,  from  which  are  made 
picric  acid  and  trinitrotoluene  respectively.  Even  benzene 
becomes  valuable  from  the  military  standpoint,  because 
from  benzene  we  can  make  phenol  and  so  make  picric 
acid.  The  very  first  thing,  therefore,  that  a  Government 
does  on  the  outbreak  of  war,  is  to  commandeer  huge 


THE  ROMANCE  OF  EXPLOSIVES     81 

supplies  of  benzene,  toluene,  phenol  and  similar  coal  tar 
products.  Great  care,  too,  is  taken  to  prevent  the  export 
of  such  chemicals  to  foreign  countries,  where  they  could 
be  used  for  making  ammunition  for  sale  to  the  enemy. 

Mercury  fulminate,  C2N2O2Hg2,  is  a  most  dangerous 
and  sensitive  explosive  much  used  for  making  percussion 
caps,  detonating  fuses,  and  the  like.  It  may  be  prepared 
by  dissolving  mercury  in  nitric  acid  and  then  adding  alcohol 
to  the  solution.  A  violent  action  soon  begins,  dense  clouds 
of  white  and  then  orange  coloured  vapours  are  evolved, 
and  the  mercury  fulminate  is  precipitated  in  small,  gray, 
beautifully  formed  crystals,  which  are  washed  with  water 
and  stored  wet  in  guttapercha  vessels.  A  slight  blow 
will  cause  it  to  explode  with  a  loud  detonation,  and  the 
easy  method  of  preparation  has  caused  it  to  be  much  used 
by  anarchists  in  their  'bombs. 

Last  of  all  we  will  mention  a  curious  explosive  called 
Nitrogen  Chloride.  In  the  year  1811  it  occurred  to  a 
famous  French  savant  called  Dulong,  to  pass  chlorine  gas 
into  a  strong  solution  of  ammonium  chloride  (sal  am- 
moniac). To  his  surprise  he  noticed  that  a  peculiar 
yellow  oil  began  to  collect  at  the  bottom  of  the  vessel. 
He  collected  a  small  amount  of  it  and  began  to  examine 
its  properties  more  closely,  when  all  of  a  sudden  it  ex- 
ploded with  terrific  force,  blowing  out  the  unfortunate 
man's  eye  and  shattering  into  a  pulp  three  of  his  ringers. 
This  compound  is  now  known  to  be  nitrogen  chloride, 
and  is,  perhaps,  the  most  dangerous  explosive  known.  Its 
formation  may  be  represented  thus : 

NH4C1        +    3C12  =         NC13        +         4HC1 

Ammonium  chloride      Chlorine      Nitrogen  chloride      Hydrochloric  acid 

Wishing  to  preserve  others  from  a  like  accident, 
Dulong  kept  his  knowledge  to  himself  and  so  it  came 
about  that  a  similar  accident  happened  in  1813  to  Fara- 

F 


82     MODERN   CHEMISTRY  AND   ITS  WONDERS 

day  and  Davy.  Faraday  was  holding  a  small  tube  con- 
taining a  few  grains  of  this  yellow  fluid  between  his 
finger  and  thumb,  when  he  was  stunned  by  a  bright 
flash  followed  by  a  violent  thunderlike  explosion.  On 
returning  to  consciousness  he  found  himself  standing 
with  his  hand  in  the  same  position,  but  torn  by  the 
shattered  tube,  and  the  glass  of  a  thick  mask  he  was 
wearing  cut  by  the  projected  fragments.  The  substance 
is,  in  fact,  terribly  explosive.  The  slightest  touch  of  an 
oiled  feather,  a  beam  of  sunlight  falling  upon  it,  or  some 
slight  vibration  like  that  caused  by  a  door  slamming  in 
the  distance,  may  cause  it  to  explode. 

Nitrogen  chloride  is  composed  of  two  elements,  both 
of  which  are  gaseous  at  ordinary  temperatures,  and  they 
are  held  together  in  the  liquid  form  by  very  weak 
chemical  forces.  The  explosion  is  simply  the  sudden 
resolution  of  the  oily  liquid  into  its  component  gases, 
nitrogen  and  chlorine,  thus : 

2NC13       =     N2     +  3C12 

Nitrogen  chloride      Nitrogen      Chlorine 

A  substance  like  this,  however,  is  far  too  dangerous  to 
be  of  any  practical  use  as  an  explosive. 

After  all  the  various  accidents  and  disasters  which 
have  been  related  in  the  preceding  pages,  the  reader  will 
be  rather  surprised  to  hear  that  commercial  explosives 
are  comparatively  safe  substances  when  properly  handled. 
So  safe  are  they,  in  fact,  that  this  often  actually  leads 
to  disaster  by  the  indifference  with  which  workmen 
handle  them.  There  are  cases  on  record  where  work- 
men have  melted  frozen  nitro-glycerine  in  a  frying  pan  over 
an  ordinary  fire  !  While  in  mining  districts  the  miners 
will  often  carry  about  in  their  pockets  dynamite  cartridges, 
which  if  exploded  would  blow  them  to  pieces. 

Indeed  only  a  short  time  ago  a  rather  curious   case 


THE    ROMANCE    OF    EXPLOSIVES  83 

happened  near  Nottingham.  It  chanced  that  two  miners, 
accompanied  by  a  friend,  were  taking  a  walk  on  a  Sunday 
afternoon  on  a  waste  bit  of  ground  in  the  neighbour- 
hood. They  wished  to  show  this  friend  the  effect  of 
an  explosion,  and  so  one  of  them  pulled  out  a  cartridge 
from  his  waistcoat  pocket,  applied  a  light  to  the  fuse,  and 
threw  the  cartridge  to  a  safe  distance. 

Now  every  miner  has  a  dog,  who  takes  an  intelligent 
interest  in  all  that  his  master  does.  No  sooner  did  the 
little  animal  see  an  object  whirling  through  the  air  than 
he  immediately  thought  that  this  was  something  thrown 
for  his  especial  benefit,  and  that  he  was  required  to  fetch 
it,  and  raced  in  pursuit.  He  caught  the  cartridge  in  his 
mouth  and  then  came  running  back  towards  the  men. 
These,  horror-stricken,  fled  wildly,  with  the  dog  pursuing 
them.  Although  the  miners  developed  a  record  speed, 
the  dog  soon  caught  them  up.  Luckily  the  dog  had, 
by  seizing  the  fuse,  put  it  out,  and  so  the  situation  was 
saved. 

And  now  I  should  like  to  say  a  few  words  about  a 
subject  on  which  a  great  deal  of  misapprehension  exists. 
If  in  the  case  of  modern  high  explosives  we  have  com- 
mand of  powers  so  vast  that  mountains  can  be  rent 
asunder  and  steel  twisted  and  shattered  as  if  made  of 
paper,  why  cannot  we  apply  these  same  powers  for  driv- 
ing engines  ?  Would  not  these  same  powers  placed  in 
the  cylinders  of  engines  of  suitable  construction  drive 
them  with  far  greater  power  than  the  ordinary  propellant- 
agent  powers,  such  as  gas,  steam,  oil  and  electricity  ?  The 
answer  is  that  there  is  far  more  work  to  be  obtained  out 
of,  say,  1  Ib.  of  coal  or  petroleum,  than  out  of  the  same 
weight  of  dynamite,  and  that  explosives  are  only  valuable 
technically  because  they  liberate  their  energy  in  a  very  short 
time.  For  instance  1  kilogram  of  liquid  petroleum  when 
burnt  develops  the  amount  of  heat  represented  by  12,000 


84     MODERN   CHEMISTRY  AND   ITS  WONDERS 

calories,  and  average  coal  about  8000  calories,  whereas 
1  kilogram  of  dynamite  (with  25  per  cent,  kieselguhr)  will 
only  develop  1300  calories. 

So  that  the  amount  of  energy  liberated  by  burning 
1  kilogram  of  petroleum  or  coal  would  cause  an  engine 
to  do  eight  or  nine  times  the  amount  of  work  that  could 
be  obtained  by  causing  the  engine  to  be  set  into  motion 
by  the  power  liberated  by  decomposing  the  same  weight 
of  dynamite.  Also  the  actual  utilisation  of  the  energy 
liberated  by  explosives  compares  very  unfavourably  with 
that  of  a  high-class  engine  of  the  Diesel  type,  where  the 
efficiency  may  rise  to  37  per  cent,  of  the  theoretical, 
whereas  in  an  engine  driven  by  explosives  the  efficiency 
is  only  15  to  20  per  cent,  of  the  theoretically  possible. 
Consequently  the  employment  of  high  explosives  as  motive 
agents  has  little  prospect  of  success. 

All  explosives  are  substances  in  a  state  of  strain,  from 
which  they  release  themselves  when  they  explode.  They 
may  be  compared  to  compressed  springs  which  contain 
energy  stored  up  in  them  which  they  give  out  when 
they  perform  mechanical  work.  All  explosives,  therefore, 
contain  energy  stored  up  in  them,  and  'this  energy  mani- 
fests itself  when  they  decompose  in  the  production  of 
heat  and  the  increase  of  volume  which  is  so  characteristic 
a  concomitant  of  explosions.  Explosive  compounds  must 
have  this  energy  put  into  them  at  the  moment  of  their 
formation.  In  other  words,  they  must  be  formed  from 
their  elements  with  the  absorption  of  heat.  It  is  the 
heat  which  thus  disappears  in  them  when  they  are  formed 
which  reappears  again  when  they  explode,  and  which 
gives  them  their  awful  power.  And  experiment  confirms 
theory.  It  is  found  that  the  heats  of  formation  of  explosive 
compounds  are  negative.  In  other  words,  they  are  formed 
from  their  elements  with  the  absorption  of  heat. 

Now  it  is  quite  incorrect  to  assume  that  very  high 


THE    ROMANCE    OF    EXPLOSIVES  85 

temperatures  decompose  all  chemical  compounds  into 
their  elements.  The  science  of  thermo-dynamics  teaches 
us  that  with  rising  temperature  those  compounds  tend  to 
be  formed  whose  production  is  attended  with  the  absorp- 
tion of  heat.  Thus,  in  the  electric  arc  at  3000°  C. 
oxygen  and  nitrogen  unite  together,  heat  being  ab- 
sorbed in  the  process.  Further,  the  well-known  com- 
pounds benzene  and  acetylene  are  formed  from  their 
elements,  carbon  and  hydrogen,  at  the  very  highest 
temperatures,  with  the  absorption  of  heat.  Moissan 
has  shown  that  at  the  enormous  temperature  of  the 
electric  arc  carbon  unites  directly  with  many  elements 
to  form  compounds  called  "  carbides."  A  large  number 
of  these  are  formed  from  their  elements  with  the  absorp- 
tion of  heat  and  will  explode  when  struck  at  ordinary 
temperatures,  then  evolving  the  heat  they  had  absorbed 
in  their  formation  at  high  temperatures.  In  general  the 
higher  the  temperature  at  which  a  reaction  takes  place 
the  greater  is  the  quantity  of  heat  that  is  absorbed  by  it. 
A  similar  law  prevails  for  the  influence  of  pressure.  An 
increase  of  pressure  favours  the  formation  of  products 
which  have  small  volumes.  In  other  words,  a  very  high 
temperature  combined  with  a  very  high  pressure  will  tend 
to  produce  compounds  containing  a  very  large  amount 
of  heat  stored  up  in  them,  and  possessing  a  very  small 
volume.  Such  compounds,  therefore,  should  exhibit 
explosive  properties.  For  when  they  decompose  they 
liberate  all  the  large  quantities  of  heat  stored  up  in  them, 
and  at  the  same  time  they  will  form  products  of  a  greater 
volume  than  themselves  and  thus  generate  a  sudden 
pressure. 

Arrhenius *  has  been  led  by  these  considerations  to 
put  forward  some  interesting  theories  to  account  for  the 
stupendous  explosions  which  take  place  on  the  sun,  and, 

1  Das  Werden  der  Welten,  pp.  82-84.    1908, 


86     MODERN  CHEMISTRY  AND   ITS  WONDERS 

doubtless,  on  all  the  visible  stars.  He  believes  them  to 
be  due  to  the  action  of  explosive  compounds  which  are 
produced  in  the  interior  of  the  sun  under  the  enormous 
temperatures  and  pressures  there  prevailing.  When  these 
compounds  are  brought  up  near  the  surface  again  by 
the  violent  movement  going  on  all  over  and  inside  the 
giant  mass,  they  explode  with  enormous  power,  shooting 
aloft  a  column  of  molten  and  gaseous  debris  thousands 
of  miles  long  and  billions  of  tons  in  weight.  A 
dynamite  explosion  can  scarcely  ever  hurl  a  projectile 
more  than  a  few  thousand  feet  a  second,  but  these 
celestial  explosives  hurl  millions  of  tons  of  matter  aloft 
at  the  rate  of  hundreds  of  miles  a  second.  They  have 
an  energy  millions  of  times  greater  than  any  explosive 
ever  made  by  man. 

Arrhenius  pictures  the  gases  of  the  upper  levels  of  the 
sun's  atmosphere  rushing  downwards  into  the  mighty 
depths  of  his  body,  just  as  we  see  them  doing  in  sunspots. 
As  they  plunge  downwards  towards  the  interior  the 
pressure  keeps  on  increasing  enormously,  the  increase 
being  about  3500  atmospheres  per  kilometre  descended. 
At  the  same  time  the  temperature  rapidly  rises,  flaring 
up  to  the  giant  heat  of  many  millions  of  degrees  centi- 
grade. Under  these  conditions  they  unite  to  form  com- 
pounds. Yes,  the  very  gases  which,  in  consequence  of 
the  high  temperatures  and  low  pressures  prevailing  in  the 
outermost  levels  of  the  sun  (outside  the  clouds  of  the 
photosphere),  fall  apart  into  atoms,  enter  into  chemical 
combination  in  the  depths  of  the  sunspots.  But  what 
strange  compounds  are  these  !  They  are  utterly  unlike 
any  that  we  know  upon  the  earth.  They  require 
enormous  quantities  of  heat  for  their  formation,  quantities 
which  transcend  those  required  for  the  formation  of 
earthly  chemical  compounds  in  the  same  degree  that 
the  temperatures  in  the  sun  transcend  those  at  which 


THE    ROMANCE    OF    EXPLOSIVES  87 

chemical  processes  proceed  upon  the  earth.  We  must 
therefore  picture  to  ourselves  that  deep  in  the  interior 
of  the  sun  there  exist  compounds  which  when  brought 
to  the  surface  suddenly  flash  with  an  appalling  roar  into 
their  elementary  atoms  again,  liberating  as  they  do  so 
the  enormous  quantities  of  stored  up  heat,  and  vastly 
increasing  in  volume.  Such  compounds  must  be  regarded 
as  the  mightiest  of  all  explosives,  in  comparison  to 
which  all  earthly  explosives  are  mere  playthings.  We 
indeed  can  form  no  conception  of  their  titanic  energy. 
We  see  their  effects  when  billions  of  tons  of  gases  come 
bursting  through  the  photospheric  clouds  which  surround 
the  sun  and  go  rushing  upwards  for  hundreds  of  thousands 
of  miles,  often  with  velocities  that  are  to  be  measured  in 
hundreds  of  miles  a  second.  These  velocities  exceed  a 
thousand-fold  those  of  our  swiftest  gun  projectiles,  and 
consequently  the  explosives  in  the  interior  of  the  sun 
must  be  over  a  million  times  more  powerful  than  earthly 
explosives,  for  the  energy  increases  with  the  square  of 
the  velocity  produced.  That  there  can  really  exist  sub- 
stances so  rich  in  energy  is  shown  by  the  case  of  radium. 
This,  as  shown  by  Rutherford,  will  liberate  before  decom- 
posing a  thousand  million  calories  per  gram  mass — a 
quantity  of  heat  which  exceeds  that  produced  by  the 
burning  of  an  equal  weight  of  coal  nearly  250,000  times. 
These  ideas  of  Arrhenius  are  interesting  because  they 
give  us  a  glimpse  into  a  hitherto  undreamt  of  region  of 
chemistry,  which  only  comes  into  existence  under  the 
stupendous  temperatures  and  pressures  prevailing  in  the 
stars,  and  which  we  can  never  hope  to  attain  in  our  earthly 
laboratories. 


CHAPTER    IV 

RADIUM    AND    THE    NEW    CHEMISTRY 

NEARLY  three  hundred  years  ago  there  appeared  a  vision 
to  the  immortal  William  Shakespeare  when  at  the  summit 
of  his  mental  activity,  and  he  wrote  it  down  as  follows  in 
the  phraseology  of  his  age : — 

"  And  like  the  baseless  fabric  of  a  vision 
The  cloud-capped  towers,  the  gorgeous  palaces, 
The  solemn  temples,  the  great  globe  itself, 
Yea,  all  which  it  inherit,  shall  dissolve, 
And,  like  this  insubstantial  pageant  faded, 
Leave  not  a  rack  behind." 

It  was  not,  however,  until  quite  recently  that  men  dis- 
covered that  this  picture  of  a  world  fading  away  is  pro- 
bably a  literally  true  one  of  what  is  actually  taking  place 
in  Nature  to-day.  Modern  discovery  has  made  it  ex- 
tremely probable  that  the  elements  are  not  eternal,  as 
we  once  thought,  but  are  themselves  in  change,  withering 
away  with  age  like  all  other  things.  Even  the  very 
atoms,  those  foundation  stones  of  the  universe,  are  now 
thought  to  be  born,  grow  old,  and  die. 

This  immense  revolution  in  human  thought  all  arose 
from  a  chance  observation  of  the  great  French  physicist, 
Becquerel,  in  1896.  It  appears  that  he  was  examining 
compounds  of  a  heavy  element  called  Uranium,  when  he 
made  the  startling  discovery  that  even  in  the  dark  it 
affected  a  photographic  plate  like  sunlight.1  At  the  same 

1  Niepce  de  Saint-Victor  appears  to  have  been  the  first  who  discovered  this 
fact  many  years  ago.  Le  Bon  claims  to  have  anticipated  Becquerel  in  some  of 
his  work. 

83 


RADIUM    AND   THE    NEW    CHEMISTRY      89 

time  the  air  all  around  the  uranium  compounds  was 
found  to  have  acquired  the  power  of  conducting  electricity 
and  soon  discharged  the  most  carefully  insulated  electro- 
scope. 

A  great  impetus  was  given  to  these  researches  when  a 
lady,  Madame  Curie,  traced  many  of  these  results  to  the 
presence  of  a  mysterious  new  element  which  she  called 
"  Radium."  The  ray-emitting  power  of  this  new  element 
was  perfectly  astonishing  ;  it  possessed  nearly  two  million 
times  the  activity  of  an  equal  quantity  of  uranium.  What 
distinguished  this  element  from  any  other  one  previously 
known  was  that  it  was  continually  shooting  out  into  space 
with  incredible  velocities  tiny  electrified  particles  which, 
falling  upon  a  photographic  plate,  produced  the  effect  of 
sunlight.  The  flying  particles,  moreover,  rendered  all  the 
air  around  electrically  conductive  and  so  caused  the 
discharge  of  any  electrified  body  in  the  neighbourhood. 
The  wonder  increased  when  it  became  known  that,  weight 
for  weight,  radium  was  by  far  the  most  dangerously  poison- 
ous of  all  the  known  elements.  It  even  poisons  at  a  distance, 
in  that  the  tiny  electrified  particles  shot  off  from  it  become 
embedded  in  the  flesh  of  animals  and  cause  virulent  sores 
and  ulcers  which  take  months  to  heal.  Indeed  I  suppose 
that  if  ever  it  is  found  possible  to  collect  a  ton  of  the 
element  together  into  one  place  it  will  be  found  to  be 
certain  and  agonising  death  to  approach  to  within  a  yard 
or  two  of  it,  even  if  actual  contact  with  the  element  is 
avoided  altogether. 

In  addition  to  being  the  most  poisonous  element 
known,  radium  also  enjoys  the  distinction  of  being  the 
most  expensive  substance  at  present  purchasable  upon 
the  earth's  surface.  In  1913,  for  example,  the  market 
value  of  radium  was  about  £16,000  a  gramme,  or  in  Eng- 
lish measures,  £450,000  an  ounce,  £7,200,000  a  pound  1 

This    enormous   costliness  has,   and   is   now,   driving 


90     MODERN   CHEMISTRY  AND  ITS  WONDERS 

mineral  prospectors  all  over  the  world  into  the  most 
unlikely  and  wild  regions  in  the  hope  of  alighting  on 
some  great  sources  of  radium,  hitherto  undetected  on 
account  of  the  inaccessibility  of  the  country.  Weird 
have  been  the  stories  told  of  dangers  and  escapes  of 
these  bold  pioneers  of  civilisation.  Indeed  some  have 
even  perished  miserably  in  their  search,  one  of  the 
saddest  cases  being  that  of  Mr.  J.  H.  Warner,  who,  in  1913, 
with  two  natives  penetrated  into  unexplored  parts  of 
Papua  (New  Guinea).  He  was  killed  and  eaten  by  the 
ferocious  natives  of  that  part,  his  two  companions 
escaping. 

But  another  and  more  astonishing  fact  was  soon  dis- 
covered. It  was  this  :  unlike  anything  else  previously 
known,  and  apparently  in  contradistinction  to  all  known 
laws  and  theories,  radium  was  found  to  be  hourly  emitting 
very  large  quantities  of  heat,  without  itself  undergoing 
any  noticeable  amount  of  change,  either  physically  or 
chemically.  And  this  heat  evolution  continued,  without 
noticeable  signs  of  diminution,  hour  after  hour,  day  after 
day,  century  after  century,  for  thousands  of  years.  Curie 
and  Laborde  found  that  in  a  single  hour  a  piece  of 
radium  emitted  enough  heat  to  raise  an  equal  weight  of 
water  from  its  freezing  point  to  its  boiling  point.  One 
ton  of  radium  enclosed  in  a  suitable  boiler  would  cause 
one  ton  of  water  to  boil  within  one  hour,  and  would  keep 
it  boiling  continually  for  more  than  a  thousand  years. 

The  energy  given  off  by  12  pounds  of  radium,  if  fully 
utilised  under  the  boiler  of  a  perfect  steam  engine,  would 
develop  one  horse-power  continuously. 

The  reader  can  easily  calculate  from  this  that  32  tons 
of  radium  in  the  furnaces  of  a  great  liner  like  the  Maure- 
tania  would  propel  the  ship  by  developing  the  same 
power  as  is  now  generated  by  the  daily  combustion  of 
some  hundreds  of  tons  of  coal  under  her  boilers.  However, 


RADIUM    AND    THE    NEW    CHEMISTRY      91 

32  tons  of  radium  would,  in  the  first  place,  be  unattain- 
able ;  and  in  the  second  place,  even  if  obtainable,  this 
amount  of  radium  would  cost  at  present  prices  some 
£500,000,000,000.  The  annual  interest  on  this  vast 
capital  expenditure  would  be  at  least  £20,000,000,000,  a 
sum  which  in  itself  would  more  than  pay  for  all  the  coal 
consumed  by  all  the  ships  in  the  world,  for  I  do  not  know 
how  many  thousands  of  years  to  come.  The  prospects, 
therefore,  of  employing  radium  for  driving  steamships 
do  not  look  particularly  rosy.  Moreover,  even  supposing 
the  discovery  of  some  vast  deposits  of  radium  in  the 
future  in  some  wild  country  should  solve  the  problem  of 
supplying  tons  of  radium  at  a  moderate  cost,  nevertheless, 
our  difficulties  would  not  be  overcome.  For,  as  al- 
ready mentioned,  radium  is  by  far  the  most  poisonous 
substance  known,  emitting  vapours  and  effluvia  which  are 
perfectly  deadly ;  consequently  the  isolation  of  the 
radium  in  such  masses  so  as  to  render  the  escape  of  all 
deadly  rays  and  effluvia  impossible,  would  be  a  decidedly 
difficult  engineering  feat. 

However  this  may  be,  I  think  that  it  will  be  quite 
clear  to  the  reader  that  this  new  element  is  spontaneously 
emitting  simply  enormous  amounts  of  energy.  Conse- 
quently men  quickly  realised  that  they  were  in  the 
presence  of  an  altogether  new  order  of  phenomena, 
unlike  anything  that  had  ever  been  perceived  upon  the 
earth  before.  And  soon  the  most  advanced  thinkers  were 
at  work,  explaining  these  remarkable  properties  of  the 
new  element. 

The  present  writer  was,  I  believe,  the  first  to  suggest 
the  correct  explanation,  namely,  that  the  radio-active 
elements  are  decomposing  elements.1 

1  My  attention  has  been  called  to  the  following  passage,  which  occurs  in  the 
preface  of  Mr.  Soddy's  interesting  book,  entitled  The  Interpretation  of  Radium 
(1909) : — "  The  present  day  interpretation  of  radium,  that  it  is  an  element  under- 


92     MODERN   CHEMISTRY  AND   ITS  WONDERS 

This  conclusion  was  later  confirmed  by  Rutherford 
and  Soddy,  who  actually  isolated  the  elementary  products 
of  the  decomposition  of  the  elements.  And  so  it  was 

going  spontaneous  disintegration,  was  put  forward  in  a  series  of  joint  scientific 
communications  to  the  Philosophical  Magazine  of  1902  and  1903  by  Prof* 
Rutherford  .  .  .  and  myself." 

I  should  like  to  point  out  here  that  Messrs.  Rutherford  and  Soddy  were  not 
the  first  to  suggest  that  the  radio-active  elements  are  dissociating  elements.  So 
far  as  I  am  aware,  the  first  definite  statement  to  that  effect  occurs  in  the  Chemical 
News  of  May  2,  1902,  in  a  paper  by  myself  entitled  The  Radio-active  Elements 
considered  as  Examples  of  Elements  undergoing  Decomposition  at  Ordinary 
Temperatures,  together  with  a  Discussion  of  their  Relationship  to  other 
Elements. 

In  my  paper  the  following  very  definite  statement  occurs : — "  For  many  years 
there  has  been  a  general  disposition  to  revive  the  ancient  notion  that  all  matter  is 
composed  of  a  common  '  protyle,'  and  that  the  elements  have  been  formed  from  it 
by  a  successive  series  of  condensations.  And  undoubtedly  powerful  experimental 
evidence  has  been  furnished  by  the  spectroscopic  researches  of  Sir  Norman 
Lockyer,  who  believes  that  the  terrestrial  elements  are  more  or  less  completely 
dissociated  into  substances  of  a  simple  constitution  at  the  high  temperatures  pre- 
vailing in  the  sun  and  stars.  But  what  has  hitherto  been  wanting  is  some  ex- 
perimental evidence  that  the  elements  do  actually  dissociate  at  temperatures 
attainable  in  the  laboratory.  But  it  appears  that  we  now  have  this  evidence,  for 
the  radio-active  elements  appear  to  be  actually  decomposing  at  ordinary  tempera- 
tures." It  is  also  definitely  stated  that  "  radio-activity  "  is  a  general  property  of 
matter — a  conclusion  now  generally  accepted.  The  paper  attracted  attention  in 
America,  and  Prof.  Baskerville,  in  his  Presidential  Address  to  the  Chemical 
Section  of  the  American  Association  (see  Naturct~Ft\>.  25,  1904,  p.  403),  did  me 
the  honour  of  referring  to  my  paper  as  follows: — "  Many  have  theorised  as  to  the 
ultimate  composition  of  matter.  The  logic  of  Larmor's  theory  (Phil.  Mag,, 
December,  1897,  p.  506),  involving  the  idea  of  an  ionic  substratum  of  matter,  the 
support  of  J.  J.  Thomson's  experiments  (Phil.  Mag.,  October,  1897,  p.  312),  the 
confirmation  of  Zeemann's  phenomenon,  the  emanations  of  Rutherford,  Martin's 
explanations  (Chemical  News,  1902,  Ixxxv.,  205),  cannot  fail  to  cause  credence 
in  the  correctness  of  Crookes's  idea  of  a  fourth  state  of  matter."  Messrs.  Ruther- 
ford and  Soddy,  therefore,  cannot  be  credited  with  being  the  first  to  put  forward 
the  theory  that  the  radio-active  elements  are  slowly  decomposing.  What  they 
have  done  is  to  confirm  by  their  brilliant  experimental  work  my  main  thesis  as 
regards  the  nature  of  the  radio-active  elements.  Their  first  paper,  "  The  Radio- 
activity of  Thorium  Compounds"  (fourn.  Chem.  Soc.,  1902,  Ixxxi.,  321),  con- 
tains no  statement  of  this  theory.  Their  second  paper  (loc.  cit.t  p.  837)  contains 
on  p.  859  a  statement  of  the  theory  in  cautious  language ;  this  paper,  however, 
was  only  published  in  June,  1902,  after  the  appearance  of  my  paper.  Messrs. 
Rutherford  and  Soddy's  first  communication  to  the  Philosophical  Magazine  "  On 
the  Cause  and  Nature  of  Radio-activity"  was  published  only  in  September,  1902, 


RADIUM    AND   THE    NEW    CHEMISTRY      93 

that  the  dreams  of  a  whole  generation  of  the  most 
advanced  thinkers,  of  Faraday,  Brodie,  Crookes,  Herbert 
Spencer,  and  Lockyer,  were  realised  at  last,  and  it  was 
proved  that  men  had  in  radium  nothing  more  nor  less 
than  a  decomposing  element !  The  radium  atom  was 
conceived  of  as  consisting  of  an  enormous  number — a 
quarter  of  a  million — of  electrons  whirling  round  with 
the  speed  of  over  a  hundred  thousand  miles  a  second. 
As  they  whirled,  the  atom  was  supposed  to  radiate  away 
energy,  and  finally  to  burst  like  a  bubble,  shooting  out 
into  space  with  enormous  speeds  the  tiny  particles  which 
compose  it.  It  was  these  tiny  flying  electrons  that  were 
supposed  to  give  rise  to  the  rays  which  affected  a  photo- 
graphic plate.  Careful  examination  showed,  however, 
that  these  rays  were  of  no  simple  nature.  At  least  three 
different  sorts  were  evolved,  which  are  now  known  respec- 
tively as  the  a,  ($,  and  y  rays.  Besides  these  it  was 
found  that  a  peculiar  radio-active  gas,  called  an  emanation, 
was  given  off  which  obeyed  Boyle's  law,  but  was  chemi- 
cally quite  inert  and  much  resembled  the  inert  gases  of 
the  atmosphere,  namely,  Helium,  Argon,  Krypton,  Xenon, 
and  Neon.  Sir  William  Ramsay  and  Soddy  have  con- 
sidered it  to  be  an  unstable  element  of  atomic  weight  over 
200,  which  breaks  down  rapidly,  throwing  out  rays  as 
it  does  so,  and  after  a  month  it  has  lost  practically  all 
its  radio-activity.  Among  the  products  of  change  are 
Rutherford's  A,  B  and  C  varieties  of  radium  and  gaseous 
helium. 

The  a-rays  are  small  particles  shot  out  from  the 
radium  atom  with  velocities  ranging  up  to  12,000  miles 
a  second.  They  are  charged  with  positive  electricity, 
and  when  they  strike  a  screen  made  of  zinc  blende  the 
molecular  impacts  cause  a  sea  of  scintillating  points  to 
occur.  It  has  been  supposed  that  these  particles  are 
helium  atoms,  for  their  mass  has  been  shown  closely  to 


94     MODERN   CHEMISTRY  AND    ITS  WONDERS 

correspond  to  those  of  helium  atoms,  and  helium  is  known 
to  be  a  product  of  the  decomposition  of  the  radium 
emanation. 

The  /3-rays  are  tiny  particles  possessing  a  mass  of 
scarce  the  thousandth  part  of  that  of  a  hydrogen  atom. 
They  are  negatively  charged  and  fly  off  from  the  radium 
atoms  with  tremendous  velocities.  Some  of  the  particles 
possess  an  initial  velocity  of  over  160,000  miles  a  second  ! 

The  *y-rays  are  extremely  penetrating,  passing  through 
a  screen  of  aluminium  8  centimetres  thick  before  their 
intensity  is  halved.  They  travel  with  a  velocity  greater 
than  that  of  the  /5-rays,  but  their  true  nature  has  not  as 
yet  been  ascertained. 

The  existence  of  these  terrific  motions  inside  an  atom 
teaches  us  that  within  the  atoms  of  matter  there  is  a  fund 
of  energy  so  incalculably  vast  that  it  is  altogether  difficult 
to  obtain  any  clear  idea  of  it. 

It  has  been  calculated  that  a  single  ounce  of  radium, 
were  its  internal  motions  fully  available  as  motive  power, 
would  lift  ten  thousand  tons  a  mile  from  the  earth. 
Hydrogen  and  all  other  elements  probably  contain  equal 
stupendous  reservoirs  of  power,  and  it  seems  certain 
that  all  the  energies  previously  known  to  us,  which 
manifest  themselves  in  the  heat  and  light  and  electrical 
excitement  of  chemical  combination,  are  merely  overflow 
tricklings  from  the  immeasurable  ocean  of  intra-atomic 
energy.  And  now  a  solemn  thought  arises  :  Astronomy 
has  long  taught  us  that  we  inhabit  but  a  dead  ember 
swimming  wide  in  the  void  of  space, — a  grain  of  dust 
flung  at  random  into  a  fathomless  abyss  ;  we  are  lighted 
up  from  90  millions  of  miles  away  by  a  more  horrible 
hell-fire  than  ever  the  morbid  mind  of  mediaeval  priest 
conceived  ;  afar  off  and  all  around  us  other  dead  embers, 
other  flaming  suns,  wheel  and  rush  through  the  apparent 
void  often  at  the  rate  of  a  million  miles  a  day ;  the 


RADIUM    AND    THE    NEW    CHEMISTRY      95 

nearest  sun  is  far  beyond  our  reach,  the  farthest  so 
remote  that  the  mind  fails  in  its  endeavour  to  conceive 
of  the  distance.  And  so,  alone  in  space,  the  world  rushes 
forward  far  swifter  than  any  rifle  bullet  into  the  unknown, 
spinning  dizzily  as  it  flies,  surrounded  on  all  sides  by 
gigantic  fires  and  terrific  forces.  Surely,  if  we  come  to 
consider  it,  the  world  is  a  strange,  if  not  appalling 
place  of  residence.  Shipwrecked  mariners,  though  they 
cling  but  to  a  wave-swept  boom,  would  seem  safe  com- 
pared to  mankind  on  its  bullet.  And  yet,  so  uncon- 
scious are  we  of  the  motion,  to  us  our  planet  appears 
as  a  green,  commodious  home  ;  and  the  gigantic  flames 
which  rear  aloft  from  the  sun  do  but  ripen  fruit  and 
flower,  and  warm  mildly  our  smiling  summer  landscapes  ; 
and  we  unconcernedly  go  to  work,  think  our  little 
thoughts,  do  our  petty  deeds,  while  all  around  us  in  the 
darkness  the  universe  wheels  and  roars  like  a  gigantic 
machine.  Yes,  safe,  very  safe,  appears  our  little  earth  to 
us.  But  now  radium  has  revealed  a  new  and  startling 
possibility.  Are  we  not  bestriding  an  explosive  a  million 
times  more  powerful  than  any  explosive  ever  made  by 
man  ?  If  atoms  can  explode — as  radium  atoms  explode 
— and  fly  to  pieces  with  a  speed  of  a  hundred  thousand 
miles  a  second — as  radium  atoms  do — could  not  some 
sudden  shock  let  loose  this  terrific  energy  residing  in  all 
matter  atoms,  much  as  a  detonator  explodes  dynamite  or 
gun-cotton,  and  so  cause  the  whole  world  to  disappear  in 
one  enormous  flash  of  light  ?  Such  things  could  conceiv- 
ably happen,  and  the  glare  of  the  catastrophe  would  be 
heralded  to  the  distant  worlds  of  space  but  by  a  new  star 
shining  briefly  in  their  skies. 

New  stars  appear  and  disappear,  and  some  writers 
have  supposed  that  matter  can  thus,  under  suitable  con- 
ditions, explode  into  a  mist  of  flashing  ultra-atomic 
particles.  Truly,  the  recent  advances  which  science  has 


96     MODERN   CHEMISTRY  AND    ITS  WONDERS 

made  have  revealed  to  us  possibilities  undreamt  of  by  our 
forefathers,  or  even  by  the  scientists  of  a  few  decades  ago. 

A  most  interesting  observation  has  been  made  by 
Prof.  Bragg.  He  has  shown  that  the  alpha  particles 
shot  off  from  the  radio-active  elements  go  clean  through 
matter  atoms,  knocking  off  electrical  particles  in  their 
passage  and  so  making  the  air  around  a  conductor  of 
electricity.  He  proved  this  by  sending  a  stream  of  these 
alpha  particles  through  a  thin  metal  screen,  which  robbed 
each  particle  of  some  of  its  energy,  but  did  not  bring  a 
single  one  to  rest.  The  number  of  particles  in  the  stream 
remained  unchanged  until  their  velocity  had  diminished  to 
some  5000  miles  per  second,  after  which  their  subsequent 
history  could  not  be  traced.  Now  as  each  particle  must 
have  plunged  right  through  some  hundreds  of  thousands 
of  atoms  before  emerging,  we  have  in  this  the  proof  that 
the  alpha  particles  have  passed  in  their  wild  flight  clean 
through  the  metal  atoms,  much  as  a  rifle  bullet  will  pass 
clean  through  a  man. 

The  vista  opened  up  by  this  fact  will  be  brought  home 
to  the  reader  when  I  tell  him  that  now  for  the  first  time 
since  science  began  we  have  been  able  to  pass  anything 
through  an  atom.     When  two  molecules  of  a  gas  collide 
they  approach  within  a  fairly  definite  distance,  and  the 
approach  is  followed  by  a  recession  under  new  conditions 
of  motion.      Each  molecule,  however,  has  a  domain  into 
which  no  other  molecule  can  penetrate — which  is  roughly 
the  volume  swept  out  by  the  radius  of  the  molecule.     But 
the  defences  which  guard   the   molecular   domain   break 
down  before  the  onslaught  of  particles  flashing  forward 
at  the  rate  of  12,000  miles  per  second,  and  so  the  alph 
particles  crash  right  through  the  atoms,  and  their  collisio- 
are  rather  with  one  or  other  of  a  number  of  circumscrir 
and  powerful  centres  of  force  which  exist  quite  inside 
atoms  and  act  with  great  power  when  approached  wi 


RADIUM    AND    THE    NEW    CHEMISTRY      97 

distances  small  in  comparison  with  the  atomic  radius. 
Hence  we  can  pass  right  through  the  atom  an  alpha 
particle,  which  is  simply  an  atom  of  helium,  and  then 
see  what  has  happened  to  it  when  it  has  come  out  again, 
and  from  the  treatment  which  it  seems  to  have  re- 
ceived we  can  try  to  understand  what  it  has  met  with 
inside. 

Not  only  can  this  be  done  with  the  alpha  rays,  but 
also  with  the  beta  particles  (which  are  electrons)  and  the 
gamma  rays  (X-rays),  and  so  we  have  at  once  a  powerful 
instrument  for  leading  us  into  the  mystery  of  atomic 
structure  itself. 

And  thus  it  is  that  we  have  presented  to  us  possibilities 
of  obtaining  a  glimpse  of  a  world  beyond  the  atom,  and 
of  discovering  the  arrangement  of  the  interior  of  the 
atom. 

The  chemical  examination  of  radium  showed  that  it 
was  an  element  belonging  to  the  calcium,  strontium  and 
barium  group  of  elements,  but  of  a  greater  atomic 
weight  than  either  of  these.  Very  careful  determinations 
of  this  constant  by  M.  and  Mme.  Curie  gave  it  an  atomic 
weight  of  226-2  (O  =  16).  The  heat  evolved  from  radium 
was  also  found  to  be  a  secondary  effect,  the  particles 
shot  out  by  the  exploding  atom  causing  molecular  shocks 
to  the  neighbouring  molecules,  thus  generating  a  molecular 
movement  in  the  neighbourhood  which  registers  itself  as 
heat.  Curie  and  Laborde  found  that  the  temperature  of 
a  specimen  of  pure  radium  bromide  remained  constantly 
3°  C.  higher  than  that  of  the  surrounding  air. 

A  really  wonderful  feat  which  has  recently  been  per- 

rmed    is  the  actual  counting  of  the  number  of  alpha 

'Vticles   hurled   forth   per   second   by  the  decomposing 

)(io-active  elements.     When  it  is   recollected  that  each 

:  iese  particles  rushes  forth  from  the  radium  atom  at 

Prodigious  speed  of  about  12,000  miles  per  second, 

G 


98      MODERN    CHEMISTRY  AND    ITS  WONDERS 

and  that  from  one  gram  of  radium  136,000,000,000  of 
these  helium  atoms  are  expelled  per  second,  the  reader 
will  realise  what  a  remarkable  feat  this  actual  counting 
is.  And  yet  it  was  done  in  the  simplest  possible  manner 
by  two  distinct  methods.  First  of  all  is  a  method  de- 
pending upon  the  fact  that  when  an  alpha  particle  (that 
is  to  say  an  atom  of  helium)  is  expelled  from  an  atom  of 
radium  and  crashes  against  a  sheet  of  zinc  blende,  at 
the  point  where  the  helium  atom  strikes  the  blende  a 
tiny  blaze  of  light  appears.  So  that  if  we  bring  an  ex- 
tremely small  amount  of  radium  near  such  a  sheet  of 
zinc  blende  in  the  dark  and  examine  the  surface  of  the 
mineral  by  means  of  a  lens,  we  see  flashes  of  light  coming 
and  going,  appearing  like  stars  in  the  sky  ;  and  by  count- 
ing the  number  of  stars  which  thus  appear  per  second 
and  knowing  the  quantity  of  radium  producing  this  effect, 
it  is  possible  to  find  out  the  number  of  atoms  of  helium 
thus  expelled  from  the  radium  per  second.  The  other 
method  depends  upon  the  fact  that  each  atom  of  helium 
as  it  flies  through  the  air  after  being  shot  off  by  the  atom 
of  radium  renders  the  air  in  its  path  conducting.  Now 
matters  are  so  arranged  that  the  particle  in  its  flight  is 
allowed  to  pass  between  two  highly  charged  metallic 
surfaces,  which  are  insulated  from  each  other  by  rarefied 
air,  and  are  connected  to  a  galvanometer.  As  the  particle 
flies  between  them  the  air  becomes  conducting  and  an 
electrical  discharge  takes  place  from  one  to  the  other, 
causing  the  galvanometer  to  give  a  little  movement. 
When  the  next  particle  comes  flying  along  there  is 
another  movement  of  the  galvanometer,  and  by  simply 
counting  the  number  of  kicks  the  galvanometer  makes 
in  a  minute  we  can  count  the  number  of  alpha  particles 
flying  off  from  the  radium. 

Some    people  have  doubted  the  existence  of    atoms, 
but  here  we  have,  for  the  first  time  in  history,  the  direct 


RADIUM    AND    THE    NEW    CHEMISTRY      99 

effect  of  single  individual  atoms  ;  so  that,  indirectly,  the 


URANIUM/  \__.a 

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RADI-O 
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POLONIUM. 


7^  Radioactive  Elements, 

Tke periods  ar9  those 
of  half  transformation 
(offer  Rutherford}. 


FIG.  7. 


subject  of  radio-activity  has  given  a  fresh  confirmation  of 
the  atomic  theory. 


ioo     MODERN   CHEMISTRY  AND    ITS  WONDERS 

Radium  itself  is  a  comparatively  short-lived  element. 
Rutherford  has  shown  that  its  period  of  transformation — 
that  is  the  period  required  for  one-half  of  any  given 
quantity  of  the  element  to  transform  into  the  next  ele- 
ment in  the  line  of  descent — is  under  2000  years.  When 
we  consider  that  the  world  is  known  to  have  been  in 
existence  for  hundreds  of  millions  of  years,  it  is  clear 
that  unless  the  radium  is  continually  being  produced  from 
some  source  as  fast  as  it  decomposes  it  must  all  have 
vanished  millions  of  years  ago.  It  has  now  been  shown 
that  it  is  probably  being  produced  from  uranium  through 
the  intermediate  formation  of  a  new  unstable  element 
called  ionium,  and  that  the  radium  itself  then  under- 
goes further  changes  resulting  in  the  formation  of  other 
short-lived  radio-active  elements,  known  as  Radium 
A,B,C,D,E,F,G,  as  indicated  in  the  following  table 
(pp.  102,  103). 

This  table  gives  the  descendants  of  the  various  radio- 
active elements,  as  well  as  their  periods  of  half  transfor- 
mation and  the  nature  of  the  rays  they  give  out. 

As  matters  now  stand  we  are  acquainted  with  at  least 
three  distinct  families  of  radio-active  substances,  namely, 
those  which  are  referable  to  uranium  as  the  parent  or  origi- 
nating substance,  those  which  appear  to  be  derived  by 
the  break  up  of  thorium,  and  those  derived  from  actinium. 
A  very  brief  study  of  the  facts  will  show  the  reader 
that  radio-activity  is  probably  a  general  phenomenon  of 
matter,  which  is  most  pronounced  among  elements  of 
a  high  atomic  weight.  Thus  thorium  and  uranium  are 
both  radio-active,  and  are  seemingly  continually  breaking 
down  into  elements  of  lower  atomic  weight.  Indirect 
evidence  of  the  constant  ratio  of  uranium  to  radium,  as 
well  as  the  direct  evidence  of  the  formation  of  the  inter- 
mediate element  ionium,  which  is  known  to  produce 
radium  as  a  product  of  further  change,  leaves  no  doubt 


RADIUM    AND    THE    NEW   CHEMISTRY      101 

whatever  that  uranium  (atomic  weight  240)  is  slowly 
producing  radium  (atomic  weight  226),  and  that  possibly 
lead,  silver,  and  gold  are  being  similarly  produced  in  the 
earth.  More  recently  Campbell  has  shown  that  the 
element  potassium  also  appears  to  be  very  slightly 
radio-active.  If  this  is  so  it  seems  almost  certain  that  the 
whole  body  of  elements  is  changing,  so  slowly  that  in 
most  cases  we  cannot  detect  the  change  at  all,  and  that 
the  radio-active  properties  of  radium  and  thorium  are 
only  exaggerated  cases  of  a  process  which  is  taking  place 
excessively  slowly  in  all  elements  alike.1 

It  seems  certain  that  all  our  views  as  to  the  duration  of 
geological  and  astronomical  time  will  have  to  be  revised 
in  accordance  with  the  new  knowledge.  For  example,  the 
presence  of  radium  in  the  earth's  crust  has  been  held  to 
be  capable  of  maintaining  almost  indefinitely  the  internal 
heat  of  the  earth,  while  the  presence  of  2'5  parts  of 
radium  in  one  million  will  account  for  the  present  copious 
emission  of  heat  and  light  from  the  sun,  and  opens  out 
a  vista  of  almost  limitless  time  for  the  process  of  stellar 
evolution. 

But  especial  interest  has  been  roused  by  the  discovery 
that  the  amount  of  radium  disseminated  through  the 
earth's  crust  is  very  considerable.  Joly  shows  that  in 
the  sea  alone  there  exist  no  less  than  20,000  tons  of 
radium  in  solution,  while  scattered  over  the  ocean  floor, 
and  imbedded  in  it,  are  no  less  than  a  million  tons  !  All 
this  radium  has  accumulated  in  the  sea  and  in  the  sedi- 
mentary deposits  on  its  floor  as  the  result  of  the  break 
up  and  washing  away  into  the  sea  of  igneous  rocks  which 
contain  uranium,  the  parent  of  radium.  The  radium 
especially  accumulates  in  sedimentary  deposits,  where  its 

1  This  view  was  first  suggested  by  the  writer  in  the  Chemical  News,  1901, 
83,  130;  see  also  articles  by  the  writer,  Chemical  News,  1903,  88,  197;  1904, 
89,  47,  118. 


102     MODERN   CHEMISTRY  AND    ITS  WONDERS 
No.  2.     TABLE   OF   RADIO-ACTIVE   SUBSTANCES 


ELEMENT 

RADIATION 

HALF-VALUE  PERIOD 

ATOMIC  WEIGHT 

URANIUM 

a 

6  x  109  years 

238 

* 

4- 

Uranium  X  -\ 

P+y 

24-6  days 

234  (?) 

Uranium  Y  J 

ft 

1*5  days 

234 

Ionium 
4- 

a 

/   greater  than   \ 
\  20,000  years  / 

230  (?) 

Radium 

a  +  slow  p 

2000  years 

226 

4, 

4- 

Ra-Emanation 

a 

3-85  days 

222  (?) 

Radium  A 

a 

3  minutes 

218  (?) 

4 

4 

Radium  B 

P+y 

26'8  minutes 

218  (?) 

4               r 

f       ! 

a+p  +  y 

19'5  minutes 

214  (?) 

Radium  C  I 

4- 

4,           ^  C2 

P 

1'4  minutes 

214  (?) 

Radium  D  \ 

slow  /3 

16'5  years 

210  (?) 

Radio-lead  J 

4 

Radium  E 

P+y 

5  days 

210  (?) 

Radium  F  ) 
Polonium   ] 

a 

136  days 

210  (?) 
4 

Radium  G  (lead?) 





206  (?) 

ACTINIUM 

No  rays 

? 

4- 

Radio-Actinium 

a  +  j8 

19'5  days 

* 

Actinium  X 

a 

10-5  days 

4 

Emanation 

a, 

3-9  seconds 

Actinium  A 

a 

0-002  seconds 

Actinium  B 

slow  j8 

36  minutes 

4- 

Actinium  C 

a 

2'1  minutes 

4 

Actinium  D 

P+y 

3'47  minutes 

RADIUM    AND    THE    NEW    CHEMISTRY      103 
TABLE  OF  RADIO-ACTIVE  SUBSTANCES— «wiA'««*/. 


ELEMENT 

RADIATION 

HALF-VALUE  PERIOD 

ATOMIC  WEIGHT 

THORIUM                          a 
* 

Mesothorium  1              no  rays 
t 

Mesothorium  2                /3  +  7 

3  x  1010  years 
5'5  years 
6'2  hours 

232-4 

Radiothorium 
t 
Thorium  X 

a 

a  +  /3 

2  years 
3'64  days 

Emanation 

a 

54  seconds 

Thorium  A 

a 

O14  second 

Thorium  B 

slow  j3              10'6  hours 

*       fc, 

Thorium  C  J 
^           lC2                  a 

60  minutes 
very  rapid  (?) 

Thorium  D 

3'1  minutes 

heating  effect  in  time  causes  the  upheaval  of  mountain 
ranges  on  the  floors  of  the  sedimentary  deposits.  In  Joly's 
words,  "  There  is  no  more  striking  feature  of  the  part 
here  played  by  radio-activity  than  the  fact  that  the  rhythmic 
occurrence  of  depression  and  upheaval  succeeding  each 
other  after  great  intervals  of  time,  and  often  shifting 
their  position  but  little  from  the  first  scene  of  sedimenta- 
tion, becomes  accounted  for.  The  energy,  as  we  have 
already  remarked,  is  in  fact  transported  with  the  sediments 
— the  energy  (radium)  which  determines  the  place  of 
yielding  and  upheaval,  and  ordains  that  the  mountain 
ranges  shall  stand  round  the  continental  borders.  Sedi- 
mentation from  this  point  of  view  is  a  convection  of 
energy.  When  the  consolidated  elements  are  by  these 
and  by  succeeding  movements  forced  upwards  into 


104     MODERN   CHEMISTRY  AND   ITS   WONDERS 

mountains,  they  are  exposed  to  denudative  effects  greatly 
exceeding  what  affects  the  plains.  Witness  the  removal 
during  late  Tertiary  times  of  the  vast  thicknesses  of  rock 
enveloping  the  Alps.  Such  great  masses  are  hurried 
away  by  ice,  rivers  and  rain.  The  ocean  received  them  ; 
and  with  infinite  patience  the  world  awaits  the  slow 
accumulation  of  the  radio-active  energy  beginning  afresh 
upon  its  work.  The  time  for  such  events  appears  to  us 
immense,  for  millions  of  years  are  required  for  the  sedi- 
ments to  grow  in  thickness,  and  the  geotherms  to  grow 
upwards  ;  but  vast  as  it  is,  it  is  but  a  moment  in  the  life 
of  its  parent  substance,  whose  atoms,  hardly  diminished  in 
numbers,  pursue  their  changes  while  the  mountains  come 
and  go,  and  the  rudiments  of  life  develop  into  its  highest 
consummations."  l 

As  the  result  of  very  careful  investigation  of  the 
amounts  of  radium  scattered  through  the  rocks  forming 
the  crust  of  the  earth,  Joly  comes  to  the  somewhat 
alarming  conclusion  that  the  internal  temperature  of  the 
earth  must  be  increasing  steadily,  and  that  ultimately  the 
whole  earth  may  again  become  molten. 

"  A  celestial  body  possessing  any  considerable  store 
of  long-lived  radio-active  elements  will  not  cool  as  an 
ordinary  body,  simply  parting  with  its  stored  up  heat, 
and  falling  in  temperature  gradually  from  its  surface 
inwards.  .  .  .  The  quiet  accumulation  of  radio-active 
energy  proceeding  throughout  the  mass  will,  near  the 
surface,  make  good  the  radiation  loss,  but  in  the  interior, 
where  no  means  of  escape  exists,  must  collect  during  the 
passing  geological  periods.  There  can  be  but  one  result  : 
— general  surface  vulcanicity  and  reversion  to  temperature 
conditions  which  may  involve  the  repetition  of  the  entire 
sequence  of  events.  If  such  has  been  the  past  history 
of  our  globe,  and  such  the  origin  of  our  geological  age, 

1  Radio-activity  and  Geology,  pp.  111-112.   (Constable  £  Co.,  Ltd.,  London.) 


RADIUM    AND    THE    NEW   CHEMISTRY      105 

we  find  the  existing  earth-heat  to  be  more  or  less  com- 
pletely radio-active  in  origin.  .  .  .  We  have  no  reason 
to  find  in  the  advent  of  radio-activity  into  cosmic  and 
geological  sciences  any  new  difficulties,  but  rather  the 
clearing  away  of  old  ones.  The  duration  of  solar  heat 
finds  a  plausible  explanation,  and  the  prolonged  duration 
of  geological  time  without  the  corresponding  cooling  of 
the  earth's  surface  becomes  accounted  for.  But  it  cannot 
be  said  that  it  enables  us  to  foretell  the  destiny  of  our 
globe.  Unless  other  lines  of  evidence  exist,  we  are  left 
to  the  imagination  as  to  what  has  been  the  history  of  the 
past,  and  what  may  result  in  the  future.  But  wonderful 
possibilities  are  brought  before  us.  Peaceful  cooling  may 
await  the  earth  or  catastrophic  heating  may  lead  into  a  new 
era  of  life.  Our  geological  age  may  have  been  preceded 
by  other  ages,  every  trace  of  which  has  perished  in  the 
regeneration  which  heralded  our  own.  Whatever  be  the 
future  or  the  past  of  our  world,  we  have  the  untrammelled 
regions  of  space  in  which  such  varied  destinies  must 
surely  find  their  accomplishment.  The  planets  may  now 
be  in  varying  phases  of  such  great  events.  And  when  a 
star  appears  in  the  heavens  where  before  we  knew  of 
none,  may  not  this  be  a  manifestation  of  the  power  of  the 
infinitely  little  over  the  infinitely  great — the  unending 
flow  of  energy  from  the  unstable  atoms  wrecking  the 
stability  of  a  world  ?  .  .  .  With  an  interest  almost 
amounting  to  anxiety,  geologists  will  watch  the  develop- 
ments of  research  which  may  result  in  timing  the  strata 
and  the  phases  of  evolutionary  advance  ;  and  may  even 
—going  still  further  back — give  us  glimpses  of  past  aeons, 
beyond  that  day  of  regeneration  which  at  once  ushered 
in  our  era  of  life,  and,  for  all  that  went  before,  was  <  a 
sleep  and  a  forgetting.'  "  1 

1  Joly,  Radio-activity  and  Geology,  pp.  170,  172,  250  (1909).     (Constable 
and  Co.,  Ltd.,  London.) 


io6     MODERN   CHEMISTRY  AND   ITS  WONDERS 

Thus  the  reader  will  see  that  the  discovery  of  the 
radio-active  elements  has  indeed  opened  up  a  new  and 
wonderful  vista  of  possibilities,  in  the  light  of  which  we 
must  remodel  all  our  views  regarding  the  structure  of 
the  universe. 

For  example,  it  is  certain  that  Kelvin's  estimate  of  the 
earth  and  sun's  ages,  founded  on  the  physical  method  of 
treating  the  earth  and  sun  as  if  they  were  simply  cooling 
bodies,  has  been  dealt  its  death-blow  by  the  discovery  of 
radium  in  the  earth.  The  old  hypothesis  is  that  the 
earth  was  flung  off  in  a  molten  condition  from  the  sun, 
then  a  vast  incandescent  nebulous  mass,  and,  after 
separation,  the  world  slowly  cooled  to  its  present  con- 
dition— and  is  still  cooling.  Now,  assuming  the  world  to 
have  hung  in  space  as  a  molten  red-hot  globule  splashed  off 
from  a  vaster  mass  of  incandescent  liquid,  then  it  is 
certain  that  the  amount  of  radium  now  in  the  earth  would 
not  evolve  sufficient  heat  to  retard  greatly  the  cooling  of 
the  earth  up  to  the  point  when  it  became  surrounded  by 
a  solid  crust.  When  the  solid  crust  of  the  earth  has 
cooled  to  its  present  temperature  the  rate  of  heat  loss  by 
radiation  into  space  is  exactly  compensated  by  the  heat 
evolved  from  the  elementary  disintegration  of  the  radio- 
active elements  in  the  earth's  surface  rocks,  as  explained 
above  ;  and  so  a  balance  will  be  struck  and  the  present 
temperature  of  the  surface  will  be  maintained  quite 
stationary — for  a  time.  But  deep  below,  in  the  interior 
of  the  earth,  heat  is  being  continually  evolved  by  radio- 
active substances  which  cannot  escape,  and  so  there 
comes  a  time,  as  suggested  by  Professor  Joly,  when 
disaster  ensues.  But  not  from  without  by  collision  with 
some  wandering  star — as  was  once  taught — but  from 
within,  by  the  flooding  of  her  surface  with  irresistible  out- 
pourings of  white-hot  molten  lava,  is  the  destruction  to 
come  that  will  reduce  the  world  to  her  former  incan- 


RADIUM    AND    THE    NEW    CHEMISTRY     107 

descent  condition,  and  begin  again  her  life-history  perhaps 
for  the  thousandth  time. 

Similarly,  it  is  supposed  that  our  sun  will  in  like  manner 
cool  to  a  certain  surface  temperature  whereat  the  heat 
evolved  by  the  elemental  disintegration  of  the  radio-active 
material  in  the  surface  layers  will  balance  the  heat  loss 
by  radiation  from  the  surface,  until  after  some  ages  of 
cooling,  darkness  and  death  will  overtake  the  solar  system, 
and  the  planets,  hidden  by  night,  will  continue  to  circle 
ghost-like  around  our  burnt-out  sun.  And  this  will  be 
the  fate  not  of  our  own,  but  of  other  suns  as  well,  as 
described  in  Peter  McArthur's  words : 

"  The  thronged  suns  are  paling  to  their  doom, 
The  constellations  waver,  and  a  breath 
Shall  blurr  them  all  in  eternity  ; 
Then  ancient  Silence  in  oblivious  gloom 
Shall  reign  where  holds  this  dream  of  Time  and  Death 
Like  some  brief  bubble  in  a  shoreless  sea." 

But  only  for  a  time.  Age  after  age  the  heat  of  the 
decomposing  elements  accumulates  in  the  sun's  interior, and 
at  last  causes  eruptive  outburst  after  outburst  of  accumu- 
lating violence,  culminating  in  some  vast  uprush  of  incan- 
descent fiercely  heated  matter,  which  will  give  the  dark 
sun  again  its  original  intensely  hot  surface,  the  glare  of 
whose  uprising  flames  will,  after  ages  of  darkness,  light  up 
afresh  the  surrounding  planets  wheeling  in  silence  millions 
of  miles  afar,  and  awaken  them  to  life  and  activity  once 
more  by  its  beneficent  heat  and  light ;  and  so  the  dead 
planets  again  become  covered  with  busy  populations, 
complicated  civilisations,  and  great  cities.  This  stage  is 
once  more  followed  by  slow  cooling  of  the  central  sun 
and  ultimate  darkness,  when  both  planets  and  sun  roll 
through  space  as  dead  worlds  enshrouded  in  darkness 
save  where  their  volcanoes  glow  red  through  the  eternal 


io8     MODERN   CHEMISTRY  AND   ITS  WONDERS 

night.  Then  again  follows  a  fierce  blazing  up  into  in- 
candescence ;  and  so  cycle  after  cycle  is •  repeated,  time 
after  time,  until  all  is  ended  by  some  gigantic  collision 
with  a  wandering  star. 

All  this  may  occur  not  only  in  our  own  planetary 
system  but  also  among  the  countless  millions  of  suns  of 
space  with  their  attendant  planets.  These  amazing  possi- 
bilities of  the  re-birth  of  dead  worlds  were  unknown  to 
Tennyson  when  he  wrote  the  despairing  lines : 

"  Many  a  hearth  upon  our  dark  globe  sighs  after  a  vanished  face, 

Many  a  planet  by  many  a  sun  may  roll  with  the  dust  of  a 
vanished  race, 

Raving  politics,  never  at  rest — as  this  poor  earth's  pale  history 
runs, — 

What  is  it  all  but  a  trouble  of  ants  in  the  gleam  of  a  million 
million  of  suns  ? 

What  is  it  all,  if  we  all  of  us  end  but  in  being  our  own  corpse- 
coffins  at  last, 

Swallowed  in  Vastness,  lost  in  Silence,  drowned  in  the  deeps  of  a 
meaningless  Past? 

What  but  a  murmur  of  gnats  in  the  gloom,  or  a  moment's  anger 
of  bees  in  their  hive  ?  " 

In  view  of  the  wonderful  revelations  of  science  during 
the  last  few  years  we  must  decide  that  the  pessimistic 
attitude  of  Tennyson  is  unwarranted  by  the  facts  now 
known  to  us. 

It  will  be  seen,  therefore,  from  what  we  have  stated 
that  the  determination  of  the  actual  age  of  the  earth  is 
immensely  complicated  by  radio-activity.  Seeing  that 
there  are  possibly  independent  cycles  of  incandescence 
and  darkness  of  both  sun  and  earth,  even  if  we  can  make 
an  estimate  (and  there  are  several  ways  of  doing  this)  of 
the  time  which  it  has  taken  for  our  world  to  cool  from  a 
molten  condition  to  its  present  surface  temperature,  we 


RADIUM    AND    THE    NEW   CHEMISTRY      109 

cannot  exactly  tell  what  was  the  sun's  state  during  that 
time.  From  present  evidence,  however,  it  seems  very 
probable  that  the  sun  shone  brightly  long  before  the 
earth  came  into  existence  ;  it  is,  however,  also  possible 
that  the  incandescence  of  the  sun  arose  after  the  earth's 
crust  had  solidified,  and  that  the  earth  for  long  eeons  of 
ages  rolled  through  space,  cold  and  dark,  a  dead  planet, 
waiting  only  for  the  incandescence  of  a  dark  sun  to 
awaken  her  surface  to  life  activity. 

However  this  may  be,  the  subject  of  radio-activity 
allows  us  to  make  estimates  of  the  age  of  the  earth  by 
an  independent  method. 

The  principle  of  the  method  will  be  understood  when 
we  recollect  that  radium  is  an  element  descended  by  a 
slow  series  of  changes  from  uranium,  the  changes  con- 
tinually proceeding  down  a  series  of  radio-active  ele- 
ments until  a  stable  element,  probably  lead  (see  table  2, 
page  102)  is  reached.  The  process  of  degradation  is  ex- 
cessively slow,  but  the  time-rate  of  each  change  has  been 
definitely  calculated  from  laboratory  measurements.  Also 
the  number  of  helium  atoms  (i.e.  Alpha  particles)  thrown 
off  during  each  change  is  definitely  known. 

Now  two  workers,  Prof.  Joly  of  Dublin  and  the  Hon. 
R.  J.  Strutt  of  London,  assume  that  all  these  discharged 
helium  atoms  have  accumulated  in  a  given  mineral  in  situ 
in  any  geological  formation,  and  that,  consequently,  all 
we  have  to  do  in  order  to  estimate  its  age  is  to  deter- 
mine in  a  specimen  mineral  the  ratio  of  the  occluded 
helium  to  the  still  remaining  radio-active  element,  whence 
we  can  calculate  the  age  of  the  geological  formation  from 
which  the  mineral  has  been  taken. 

The  results,  however,  have  not  been  very  satisfactory, 
for  it  has  been  found  that  material  which  must  have  been 
formed  about  the  same  time  gives  ages  which  differ  very 
considerably.  The  error  probably  lies  in  the  fact  that 


no     MODERN    CHEMISTRY  AND    ITS  WONDERS 

the  helium  in  the  course  of  time  has  escaped  to  some 
extent  from  the  geological  formation  in  which  it  was  pro- 
duced ;  and  this  is  likely  enough  when  we  recollect  the 
changes  of  temperature  and  pressure  to  which  the  mineral 
must  have  been  exposed  during  the  long  ages  which  have 
elapsed  since  the  formation  of  the  mineral,  to  say  nothing 
of  the  solvent  action  of  percolating  waters. 

Professor  Boltwood  has  attacked  the  problem  from  a 
different  standpoint  by  assuming  that  lead  is  the  ultimate 
product  of  the  disintegration  of  uranium,  and  so  from 
measurements  of  the  uranium-lead  ratio  of  a  given 
mineral,  and  knowing  the  rate  of  transformation  of 
uranium  into  lead,  it  is  quite  an  easy  matter  to  calculate 
the  age  of  the  mineral,  and  so  make  estimates  of  the  age 
of  the  geological  strata  from  whence  the  mineral  was 
taken. 

The  age  of  the  earth  on  these  assumptions  works  out 
between  200  and  1300  millions  of  years.  The  evidence 
of  radio-activity  is  to  give  the  earth  an  age  greater  than 
that  adduced  by  any  other  methods. 

We  thus  see  what  a  vista  of  possibilities  the  subject  of 
radio-activity  has  opened  out.  It  has  destroyed  the 
pitiably  cock-sure  attitude  so  characteristic  of  scientists 
only  a  few  years  ago,  when  it  was  thought  that  the  con- 
stitution of  matter  and  of  the  universe  were  tolerably  well 
known,  and  that  only  a  few  minor  points  remained 
to  be  cleared  up.  Some  of  the  greatest  thinkers  of  the 
Victorian  age  went  down  to  their  graves  derided  by  these 
cock-sure  scientists.  But  the  thoughts  of  such  men  as 
Herbert  Spencer  and  Johnstone  Stoney  regarding  the 
Universe  were  considerably  nearer  the  mark  than  the 
more  conservative  assumptions  of  their  antagonists,  who 
loaded  them  with  ridicule.  Radio-activity  has,  indeed, 
revolutionised  the  mental  outlook  of  scientists.  It  has 
opened  up  a  realm  of  possibilities  previously  unthought 


RADIUM    AND    THE    NEW    CHEMISTRY     in 

of  save  by  some  old-world  thinkers.  It  has  taught  us  that 
we  cannot  doubt  that  there  are  still  greater  truths  to  be 
discovered  than  any  which  have  before  illuminated  the 
world. 

Although  we  may  see,  by  means  of  radio-active  ex- 
plosion,— 

"  Atoms  or  systems  into  ruin  hurPd, 
And  now  a  bubble  burst,  and  now  a  world." 

and  can  thus  explain  much  that  was  previously  inexplicable 
to  us,  yet  we  must  not  forget  that 

"  Beyond  the  bright  search-lights  of  Science 
Out  of  sight  of  the  windows  of  sense, 
Old  riddles  still  bid  us  defiance, 
Old  riddles  of  why  and  whence. 
There  fail  all  the  pathways  we've  trod, 
Where  man,  by  belief,  or  denial, 
Is  weaving  the  purpose  of  God." 

The  omniscience  of  Science,  in  fact,  has  received  a 
shock  by  the  discovery  of  radio-activity  in  recent  years. 
She  must  now  confess  with  Tennyson — 

"  So  runs  my  dream  ;  But  what  am  I  ? 
An  infant  crying  in  the  night ; 
An  infant  crying  for  the  light ; 
And  with  no  language  but  a  cry." 


CHAPTER    V 

THE    MYSTERY    OF    THE    PERIODIC    LAW 

IT  was  the  immortal  Wordsworth  who  sang  of 

"  Truths  that  awake, 

To  perish  never; 
Which  neither  listlessness,  nor  mad  endeavour, 

Nor  man,  nor  boy, 
Nor  all  that  is  at  enmity  with  joy 

Can  utterly  abolish  or  destroy." 

And  I  think  we  may  confidently  state  that  the  principle 
which  we  are  going  to  discuss  in  this  chapter  is  one  of 
these  grand  truths.  Its  cause  lies  hidden  deep  down 
in  the -roots  of  the  universe,  beyond  our  ken  and  strength. 
Its  origin  is  bound  up  in  those  primordial  forces  which 
brought  the  material  universe  into  being,  evolving  from 
the  womb  of  time,  in  magnificent  succession,  element 
after  element,  until  all  space  was  filled  with  them.  It 
is  the  mighty  principle  which  connects  together  all  the 
multifarious  atoms  of  which  all  things  are  built  up.  Was 
ever  so  stupendous  a  problem  set  the  intellect  of  man  as 
the  solution  of  the  cause  of  this  great  law,  this  mighty 
hieroglyphic  written  in  unknown  characters  across  the 
whole  domain  of  chemistry  ?  It  links  together  in  one 
harmonious  whole  the  stupendous  mass  of  matter  scat- 
tered throughout  this  wonderful  universe  of  ours,  and 
proclaims  the  common  origin  of  the  very  matter  of  which 
our  own  earth  is  formed  and  that  which  builds  up  the 
innumerable  worlds  of  space.  I  think,  therefore,  that 


THE    MYSTERY    OF    THE    PERIODIC    LAW      113 

the  reader  will  be  interested  if  I  attempt  to  explain  in 
simple  language  what  this  great  law  is,  and  what  attempts, 
imperfect  and  far  from  the  mark  as  they  admittedly  are, 
have  been  made  to  explain  it. 

The  enormous  number  of  apparently  unconnected 
facts  is  the  feature  of  Chemical  Science  which  most 
deeply  impresses  the  intelligent  reader  commencing  its 
study  for  the  first  time.  As  he  reads  element  after  ele- 
ment rises  into  view  on  his  intellectual  horizon,  each  the 
centre  of  a  vast  galaxy  of  compounds,  the  whole  forming 
a  bewildering  maze  of  complex  properties,  in  the  midst 
of  which  the  unaided  intellect  stumbles  helplessly  in  its 
attempts  to  fix  and  retain  them  in  orderly  array.  During 
the  first  decades  of  the  nineteenth  century  chemical 
science  advanced  rapidly  and  discovery  after  discovery 
kept  piling  fact  upon  fact  until  the  huge  edifice  was  a 
confused  jumble  constructed  without  apparent  plan  or 
order. 

But  it  was  not  long  before  some  of  the  more  original 
intellects  were  at  work,  delving  behind  the  facts,  collect- 
ing and  arranging  them,  in  the  hope  that  some  simple  but 
grand  law  would  be  found  governing  the  bewildering 
masses  of  detail,  joining  them  together  as  by  a  golden 
thread. 

Oliver  Wendell  Holmes  in  his  delightful  style  classifies 
men  into  "  One-story  intellects,  two-story  intellects,  three- 
story  intellects  with  skylights.  All  fact  collectors  who 
have  no  aim  beyond  their  facts,  are  one-story  men. 
Two-story  men  compare,  reason,  generalise,  using  the 
labours  of  the  fact  collectors  as  well  as  their  own. 
Three-story  men  idealise,  imagine,  predict ;  their  best 
illumination  comes  from  above,  through  the  skylight." 
Without  absolutely  accepting  Holmes'  classification,  it 
may  be  said  that  men  of  all  three  classes  are  to  be  met 
with  among  the  devotees  of  chemistry,  but  that  men  of 

H 


H4     MODERN   CHEMISTRY  AND    ITS  WONDERS 

the  first  class  are  especially  numerous.  This  perhaps 
was  the  reason  why,  when  the  great  generalisation  was 
at  last  revealed,  first  dimly  and  imperfectly  by  de  Chan- 
courtois  in  1862,  then  clearly  and  boldly  by  Newlands 
in  1864,  and  finally  in  all  its  grandeur  by  Mendel£eff 
and  Lothar  Meyer  between  the  years  1869  and  1871, 
that  their  brother  chemists  troubled  very  little  about 
their  labours  until  they  were  forced  to  their  notice  in 
a  truly  sensational  way.  This  happened  as  follows : 
Between  the  years  1875  and  1885  three  interesting 
new  elements  were  discovered,  now  called  Gallium, 
Germanium,  and  Scandium,  after  the  countries  of  the 
respective  discoverers.  In  the  midst  of  the  excitement 
which  always  attends  the  discovery  of  new  elements,  a 
Russian  chemist,  Mendeleeff  by  name  (see  Plate  6),  an- 
nounced that  many  years  before  he  had  not  only  predicted 
the  existence  of  these  elements,  but  had  actually  described 
their  properties.  A  reference  to  his  writings  showed  that 
this  was  really  so.  Led  by  certain  theoretical  considera- 
tions Mendeleeff  had  described  in  1871  three  elements, 
under  the  names  eka-silicon,  eka-boron,  and  eka-alumini- 
um,  whose  properties  agreed  to  an  astonishing  degree  of 
exactitude  with  those  attributed  by  their  discoverers  to 
gallium,  germanium,  and  scandium.  This  may  be  seen 
from  the  following  table,  in  which  the  predicted  properties 
and  those  actually  observed  are  arranged  in  parallel 
columns : 

Eka-boron  Scandium 

A  hypothetical  element  whose  pro-  An  element  discovered  by  Nilson 

perties  were  foretold  in  1871  by  in  1879 
Mendeleeff 

Atomic  weight,  44  Atomic  weight,  43*8 

Oxide,  Eb2O3,  Specific  gravity,  3-5  Oxide,  Sc2O3,  Specific  gravity,  3'86 

Sulphate,  Eb2(SO4)3  Sulphate,  Sc2(SO4)3 

Double  Sulphate  not  isomorphous  Sc2(SO4)3.3K2SO4 — slender    prisms 

with  alum,  A12(SO4)3,K2SO4.24H2O  not  isomorphous  with  alum. 


Photo,  V/arwick  Brooks,  Manchester. 

PLATE  G. — Mendeleeff. 


THE    MYSTERY    OF    THE    PERIODIC    LAW     115 

Eka- aluminium  Gallium 

Hypothetical  element  predicted  by  An  element  discovered  in  1875  by 

Mendele"eff  in  1871  Lecoq  de  Boisbaudran. 

Atomic  weight,  68.  Specific  gravity,  Atomic  weight,69'5.  Specific  gravity, 

6-0  5-96. 

Eka-silicon  Germanium 

Hypothetical  element  predicted  by  An  element  discovered  by  Winkler 

Mendeteeffin  1879  in  1887 

Atomic  weight,  72.   Specific  gravity,  Atomic  weight,  72.  Specific  gravity, 

5-5  5'47 

Oxide,  EsO2,  Specific  gravity,  4'7  Oxide,  GeO2,  Specific  gravity,  4'7 

Chloride,     EsCl4,     liquid,     boiling  Chloride,  GeCl4,  liquid  boiling  at 

slightly  below   100°   C.,  Specific  86°  C.,  Specific  gravity,  1-887 

gravity,  1*9 

Ethide,  Es(C2H5)4,  liquid,   boiling  Ethide,  Ge(C2H6)4,  liquid  boiling  at 

at  160°  C.,  Specific  gravity,  O96,  160°  C.,  Specific  gravity,  slightly 

slightly  less  than  water  less  than  water 

Fluoride,  EsF4,  not  gaseous  Fluoride,  GeF4.3H2O.    White  solid 

mass. 

Could  anything  be  more  wonderful  than  this  forecast  ? 
It  was  as  if  Mendel£eff  was  describing  elements  actually 
in  his  hands,  so  closely  and  accurately  was  the  forecast 
fulfilled  in  each  case.  And  yet  at  the  time  he  wrote  not 
only  were  the  elements  not  discovered,  but,  as  he  tells 
us  in  one  of  the  characteristic  footnotes  in  his  Principles 
of  Chemistry  (vol.  ii.  p.  25),  "When  in  1871  I  wrote 
a  paper  on  the  application  of  the  periodic  law  to  the  deter- 
mination of  the  properties  of  as  yet  undiscovered  elements, 
I  did  not  think  I  should  live  to  see  the  verification  of  this 
consequence  of  the  law,  but  such  was  to  be  the  case. 
Three  elements  were  described,  eka-boron,  eka-aluminium, 
and  eka-silicon  ;  and  now,  after  the  lapse  of  twenty  years, 
I  have  the  great  pleasure  of  seeing  them  discovered  and 
named  after  those  countries  where  the  rare  minerals  con- 
taining them  are  found,  and  where  they  were  discovered 
— Gallia,  Scandinavia,  and  Germany." 


n6     MODERN  CHEMISTRY  AND   ITS  WONDERS 

"  We  see  in  this  successful  three-fold  prediction," 
says  Duncan  when  discussing  this  subject  in  his  recent 
work  entitled  The  New  Knowledge,  "  the  scope  and  power 
of  the  periodic  law  as  an  instrument  of  research.  We 
see  convincingly  that  the  law  must  be  the  expression  of 
a  fact.  Suppose  that  an  astrologer  informed  you  that 
your  horoscope  led  him  to  believe  that  you  would  meet, 
sometime  in  your  life,  three  men  ;  and  that  with  the 
utmost  particularity  he  told  you  their  weights,  the  colour 
of  their  hair,  the  size  of  their  noses,  and,  in  a  word,  all 
the  habits  of  mind  and  body  sufficient  to  differentiate  them 
positively  from  all  other  men  ;  and  suppose,  moreover, 
that  you  met  these  men  possessed  of  qualities  identical 
with  the  description  predicted.  You  would  believe  in 
astrology.  Astrology  cannot  do  these  things,  but  chemistry 
can  because  of  the  periodic  law.  Therefore  we  believe 
in  the  periodic  law." 

It  can  therefore  easily  be  imagined  that  this  feat  of 
Mendele"ef¥  awakened  a  surprise  and  wonder  in  the 
scientific  world  very  similar  to  that  caused  by  the  veri- 
fication, by  the  discovery  of  Neptune,  of  Adams  and 
Leverrier's  remarkable  prediction  of  a  new  planet,  as  yet 
unseen  by  mortal  eye,  which  swung  in  a  mighty  orbit 
outside  Uranus.  Naturally  the  attention  of  the  scientific 
world  was  directed  to  the  methods  employed  by  the  great 
Russian  in  arriving  at  such  wonderful  forecasts.  And  then 
it  was  found  that,  many  years  before,  a  law  had  been  dis- 
covered by  various  workers,  independently  of  each  other, 
which  connected  all  the  elements  together  in  a  remarkable 
way,  and  regulated  their  properties.  This  was  called  the 
"Periodic  Law"  by  Mendel£eff  in  1871,  and  has  ever 
since  borne  that  name.  Let  me  now  explain  its  nature. 
By  referring  to  the  table  of  elements  given  in  any  text- 
book of  chemistry  the  reader  will  see  that  some  eighty 
odd  ones  are  there  named  and  arranged  in  alphabetical 


THE    MYSTERY    OF    THE    PERIODIC    LAW     117 

order.  But  now  let  the  reader  arrange  the  elements,  not 
in  alphabetical  order,  but  in  the  order  of  their  atomic 
weights.  Let  him,  for  example,  starting  with  lithium, 
write  the  succeeding  elements  in  the  order  of  increasing 
atomic  weight,  thus  : — 

Li  Be  B  C  N  O  F  Na  Mg  Al  Si  P  S  Cl  K 
7  9  11  12  14  16  19  23  24  27  28  31  32  35J  39 

Then  if  the  reader  will  study  the  properties  of  these  elements 
carefully  a  remarkable  fact  will  soon  appear.  It  is  this  : — 
The  series  of  elements  thus  arranged  does  not  present  one 
continuous,  progressive  modification  in  the  chemical  and 
physical  properties  of  its  several  members  with  increase 
of  atomic  weight,  but  that  the  same  properties  occur  over 
again  with  slight  modifications,  at  intervals  down  the 
series.  As  Huxley  aptly  put  it,  the  whole  series  does 
not  run 

a,  b,  c,  d,  e,  f,  g,  h,  i,  j,  k,  1,  m,  n,  o,  p,  q,  &c. 
But 

a,  b,  c,  d,  A,  B,  C,  D,  a,  ft  r,  S,  &c. 

Thus  in  the  above  series  of  elements,  Li  (lithium)  resembles 
Na  (sodium)  and  no  other  intermediate  element.  Similarly, 
carbon  (C)  resembles  silicon  (Si)  and  no  other  intermediate 
element,  fluorine  (F)  resembles  chlorine  (Cl)  and  no 
other  intermediate  element,  &c. 

John  Newlands,  a  young  man  practically  unknown  in 
chemical  circles  at  the  time,  was  the  first  who  pointed 
this  out.  Writing  to  the  Chemical  News  in  1864-5  he 
asserted  that  when  the  elements  were  thus  arranged  in 
the  order  of  the  magnitudes  of  their  atomic  weights 
"  the  eighth  element,  starting  from  a  given  one,  is  a  sort 
of  repetition  of  the  first,  or  that  elements  belonging  to 
the  same  group  stood  to  each  other  in  a  relation  similar 
to  that  between  the  extremes  of  one  or  more  octaves  of 
music." 


n8     MODERN   CHEMISTRY   AND   ITS  WONDERS 


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THE    MYSTERY   OF   THE    PERIODIC    LAW     119 

This  has  since  been  called  Newlands'  "  Law  of 
Octaves/'  and  was  a  tolerably  clear  statement  of  the 
periodic  reappearance  of  properties  when  the  weights  of 
the  atoms  are  taken  as  the  basis  of  classification  of  the 
elements.  In  1866  the  same  chemist  brought  the  rela- 
tions which  he  had  observed  to  the  notice  of  the  Chemical 
Society  of  London,  arranging  the  elements  in  a  table  so 
that  those  belonging  to  the  same  group  usually  appeared 
in  the  same  straight  line.  The  reader  will  now  suppose 
that  when  Newlands  explained  this  new  discovery  of  his 
to  that  learned  body,  the  home  of  all  the  best  chemical 
talent  in  the  country,  it  received  his  communication  with 
the  attention  that  it  deserved.  But,  alas,  I  am  sorry  to 
say,  it  did  nothing  of  the  kind.  It  required  a  powerful 
and  imaginative  intellect  to  soar  beyond  the  accumulation 
of  petty  detail  which  then  obscured  the  chemical  horizon, 
and  grasp  the  threads  of  the  great  generalisation  under- 
lying them.  It  must  be  confessed  that  Chemistry  so 
overwhelms  a  lesser  mind  with  disconnected  facts  that,  in 
the  words  of  the  proverb,  "the  wood  cannot  be  seen 
for  the  trees  "  ;  and  insensibly  there  is  produced  a  mental 
attitude  so  pithily  described  by  Tennyson : 

"  An  eye  well  practised  in  Nature,  a  Spirit  bounded  and  vain." 

At  any  rate  the  body  of  the  Chemical  Society  at  that  time 
was  largely  composed  of  the  "  one-story "  intellects  of 
Holmes'  classification,  mere  collectors  of  facts — careful 
and  accurate  analysts,  indeed,  but  devoid  of  that  scientific 
imagination  necessary  for  grasping  the  capabilities  of 
such  a  generalisation  as  Newlands  now  brought  before 
them.  And  so  it  came  about  that  his  paper  was  received 
with  open  ridicule  ;  one  prominent  chemist l  actually  got 
up  and  inquired  sarcastically  whether  the  author  had  ever 

1  Professor  G.  C.  Foster. 


120     MODERN  CHEMISTRY  AND  ITS  WONDERS 

tried  to  see  if  a  simple  law  would  appear  when  the  ele- 
ments were  arranged  in  the  order  of  the  initial  letters  of 
their  names — a  sally  of  wit  which  was  greeted  with  roars 
of  laughter.  Newlands'  paper  was  not  accepted  for  publica- 
tion, and  he  withdrew,  dismayed,  from  the  dangerous 
regions  of  theoretical  chemistry  into  the  sugar  trade.  But 
the  whirligig  of  time  brings  its  revenges.  The  Chemical 
Society  in  1866  laughed  at  Newlands  and  his  "  Law." 
But  twenty-one  years  later  the  Royal  Society  awarded 
him  the  Davy  medal  for  his  discovery. 

Newlands,  therefore,  received  some  tardy  acknowledg- 
ment of  his  work  during  his  lifetime.  But  a  predecessor 
of  his,  namely  de  Chancourtois,  did  not  even  meet  with 
this  encouragement.  He,  too,  between  the  years  1862—3, 
had  suggested  a  classification  of  the  elements  on  the  basis 
of  the  magnitude  of  their  atomic  weights,  but  his  conclu- 
sions were  so  utterly  forgotten  that  it  was  only  long  after 
his  death,  when  the  Periodic  System  had  been  firmly 
established,  that  they  were  unearthed,  and  to  some  extent 
recognised.1 

The  moral  to  be  drawn  from  this  is — Persevere.  If 
Newlands  had  only  borne  in  mind  the  teaching  of 
Davidson's  lines,2 

"  Dethrone  the  past ; 

Deed,  vision — naught 
Avails  at  last 

Save  your  own  thought." 

and  had  boldly  gone  forward,  undismayed  by  ridicule  and 
neglect,  to  deepen  and  widen  his  law  by  a  more  accurate 
study  of  the  elements,  he  could  hardly  have  failed  to 
discover  the  periodic  law  in  its  entirety. 

1  Hartog,  "A  First  Foreshadowing  of  the  Periodic  Law,"  Nature,  1892, 
41,  186. 

2  Fleet  Street  and  Other  Poems,  published  by  Grant  Richards,  London. 


THE    MYSTERY   OF    THE    PERIODIC    LAW      121 


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122     MODERN   CHEMISTRY  AND   ITS  WONDERS 


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THE    MYSTERY   OF  THE    PERIODIC    LAW      123 

As  it  was,  this  was  left  for  other  minds  to  do,  and 
a  few  years  later  the  question  was  taken  up  abroad  in 
a  wider  and  more  serious  spirit.  In  March  1869, 
Professor  D.  Mendeleeff  communicated  a  paper  to  the 
Russian  Chemical  Society  in  which  he  set  forth  an  arrange- 
ment of  the  elements  in  the  order  of  their  atomic  weights 
and  showed  that  when  thus  arrayed  the  elements  showed 
a  periodic  recurrence  of  properties.  Mendeleeff  was 
more  than  the  two-story  man  of  Holmes'  classification. 
His,  indeed,  was  a  three-story  intellect,  one  that  could  not 
only  generalise,  using  the  facts  of  others,  but  who  could 
idealise,  imagine,  and  predict.  With  a  genius  amounting, 
almost,  to  inspiration,  he  employed  the  law  not  only  to 
correct  the  atomic  weights  of  many  elements,  but,  as 
we  have  already  seen,  actually  to  predict  the  existence 
and  properties  of  elements  unknown  at  the  time.  In 
December  18  6  9,  some  nine  months  after  Mendeleeff,  Lothar 
Meyer,  then  Professor  of  Chemistry  in  the  Polytechnicum 
at  Carlsruhe,  published  a  paper  entitled  The  Nature  of  the 
Chemical  Elements  considered  as  a  Function  of  their  Atomic 
Weights,  in  which  he  gave  a  table  of  elements  substantially 
the  same  as  that  of  Mendeleeff,  and  he  likewise  remarked 
that  the  properties  of  the  elements  are  periodic  functions 
of  their  atomic  weights.  In  this  scheme  the  same  or 
similar  properties  recur  when  the  atomic  weights  are 
increased  by  a  certain  amount,  which  at  first  is  about  16, 
then  about  46,  and  afterwards  between  88  and  92. 

Meyer  also  pointed  out  that  the  combining  capacity 
of  the  atoms  rises  and  falls  regularly  and  equally  in  the 
first  two  series  of  the  elements,  thus : 

Univalent     Divalent     Trivalent     Tetravalent    Trivalent     Divalent     Univalent 

Li  Be  B  C  N  O  F 

Na          Mg  Al  Si  P  S  Cl 

In  other  words,  while  lithium  (Li)  or  sodium  (Na)  can 


124     MODERN  CHEMISTRY  AND   ITS  WONDERS 

combine  with  only  one  atom  of  an  element  like  chlorine, 
beryllium  (Be)  and  magnesium  (Mg)  can  combine  with 
two,  carbon  (C)  and  silicon  (Si)  with  four,  &c. 

But  Meyer  afforded  a  still  more  complete  and  trium- 
phant vindication  of  the  principle  of  periodicity  by  plotting 
the  relation  of  the  atomic  weights  to  the  atomic  volumes, 
as  shown  in  the  accompanying  diagram  (fig.  8).1 

Duncan,  in  graphic  language,  thus  describes  the 
phenomenon  which  then  appears.2 

"Just  as  the  pendulum  returns  again  in  its  swing, 
just  as  the  moon  returns  in  its  orbit,  just  as  the  advancing 
year  ever  brings  the  rose  of  spring,  so  do  the  properties 
of  the  element  periodically  recur  as  the  weights  of  the 
atoms  rise.  To  demonstrate  this  fact,  take  some  one 
specific  property,  for  example,  the  atomic  volume,  and 
arrange  a  table  on  a  piece  of  engineering  paper  in  which 
the  atomic  weights  read  from  left  to  right  (the  abscissae), 
while  the  atomic  volumes  read  from  bottom  to  top  (the 
ordinates).  Now  construct  a  curve  by  pricking  out  the 
positions  of  the  different  elements  in  accordance  with 
both  their  atomic  volumes  and  atomic  weights,  and  you 
will  find  yourself  in  possession  of  a  table  such  as  fig.  8. 
We  see  at  once  from  this  curve  that  the  atomic  volume 
is  a  periodic  function  of  the  atomic  weight.  As  the 
atomic  weight  increases,  the  atomic  volume  alternately 
increases  and  decreases.  The  periodicity  proclaims  itself 
in  the  regularly  recurring  hills  and  valleys  which  constitute 
the  curve.  Elements  which  occupy  similar  positions  on 
the  five  hills  and  valleys  have  markedly  similar  properties. 
Thus,  you  will  notice  at  the  summit  of  each  of  the  five 

1  The  atomic  volume  is  the  volume  occupied  by  a  weight  of  the  element  pro- 
portional to  its  atomic  weight,  the  element  being  supposed  to  be  in  the  solid 
state.     It  is  the  atomic  weight  divided  by  the  specific  gravity. 

2  The  New  Knowledge,  by   R.  K.  Duncan,  p.  23.      1906.       Hodder  & 
Stoughton,  London ;  the  A.  S.  Barnes  Co.,  New  York.     Quoted  with  permission 
of  the  publishers. 


THE    MYSTERY    OF    THE    PERIODIC    LAW 


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126     MODERN  CHEMISTRY  AND   ITS  WONDERS 

hills,  the  symbols  of  the  elements  lithium,  sodium,  potas- 
sium, rubidium  and  caesium,  all  of  these  elements  posses- 
sing amazingly  similar  properties.  Or,  again,  find  the 
little  dot  marked  S  (signifying  sulphur)  on  the  slope  of 
the  third  hill,  and  you  will  then  notice  a  little  dot 
marked  Se  (selenium)  and  another  Te  (tellurium)  in  a 
correspondingly  similar  position  on  the  two  other  hills 
respectively.  These  elements  have  strikingly  similar 
properties.  Take  now  another  property  altogether,  let 
us  say  the  melting  point  of  the  elements,  and  make  a 
similar  diagram.  You  get  a  curve  remarkably  like  the 
first  one,  with  this  exception,  that  the  elements  which 
were  at  the  top  of  the  first  curve  are  now  at  the 
bottom.  The  melting  point  curve  is  as  strictly  periodic 
as  the  atomic  volume  curve,  and  of  the  same  general 
shape.  .  .  .  Similar  curves  can  be  constructed  for  many 
other  properties.  Can  we  imagine,  then,  that  these 
atoms,  these  little  invisibilities,  in  which  we  all  live  and 
move  and  have  our  being,  are  separately  created, 
arbitrarily  made,  unrelated  individuals  ?  Hardly  so,  for 
they  are  obviously  created  in  accordance  with  some 
scheme.  Would  that  we  might  understand  this  scheme 
all  and  in  all.  It  would  be  a  veritable  glimpse  behind  the 
veil  of  existence.  But  if  we  cannot  read  from  Alpha  to 
Omega,  we  may  spell  out  what  we  can,  leaving  future 
letters  to  future  men  ;  perforce  content  that  if  in  this 
cryptogram  of  the  universe  we  know  indubitably  that 
there  is  a  cryptogram  to  be  read,  we  have  at  least  come 
to  the  beginnings  of  knowledge." 

In  August  1871  Mendeleeff  drew  up  a  complete  ex- 
position of  the  periodic  law,  and  of  the  deductions  which 
may  be  made  from  it.  Here  for  the  first  time  appeared 
the  table  which  is  now  to  be  found  in  the  pages  of  nearly 
every  text-book  of  theoretical  chemistry,  and  which  is 
employed  as  the  most  generally  received  basis  of  the 


THE    MYSTERY  OF    THE    PERIODIC    LAW      127 


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128     MODERN   CHEMISTRY  AND   ITS  WONDERS 

classification  of  the  elements.  Mendeleeff's  latest  formu- 
lation of  his  system,  drawn  up  a  few  years  before  his 
death,  is  as  shown  on  page  129.  It  will  be  seen  that  this 
scheme  differs  from  its  old  classical  form  by  the  addition 
of  the  new  elements  contained  in  the  atmospheric  air, 
which  were  discovered  by  the  recent  epoch-making 
researches  of  Sir  William  Ramsay.  These  elements  appear 
to  be  unable  to  combine  with  other  elements,  and  so 
Mendeleeff  places  them  in  a  special  group  0  containing 
elements  without  valency.  He  also  introduces  two  hither- 
to undiscovered  elements,  which  he  terms  X  and  Y,  and 
places  them  in  the  non-valent  group.  To  both  of  these 
he  attributes  an  atomic  weight  less  than  that  of  hydrogen. 
The  element  Y  is  believed  to  be  identical  with  a  very 
light  element  called  coronium  which  occurs  in  the  sun's 
atmosphere,  floating  high  up  and  flashing  out  a  brilliant 
green  light.  He  attributes  to  it  the  atomic  weight  Of4 
or  less. 

The  element  X  he  calls  Newtonium,  in  honour  of 
the  great  physicist,  and  calculated  that  its  atomic  weight 
was  about  O'OOOOOl,  or  about  five  hundred  times  lighter 
than  electrons.  Mendeleeff  further  supposed  that  this 
element  formed  the  substance  of  which  the  luminiferous 
ether  is  built  up. 

The  periodic  system  as  it  comes  from  the  hands  of 
Mendeleeff  still  suffers  from  many  imperfections.  The 
properties,  for  example,  do  not  always  correspond  to  the 
atomic  weights.  Argon,  with  an  atomic  weight  of  39*8, 
occurs  before  and  not  after  potassium  with  an  atomic 
weight  of  39'1.  The  same  applies  to  tellurium  (127-6), 
which  should  have  an  atomic  weight  intermediate  between 
that  of  antimony  (120)  and  iodine  (126-9). 

Again,  in  different  grades  of  combination  elements 
assume  entirely  different  properties.  Divalent  iron,  for 
example,  differs  very  much  in  properties  from  trivalent 


THE    MYSTERY    OF   THE    PERIODIC    LAW     129 


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130     MODERN  CHEMISTRY  AND   ITS  WONDERS 

iron,  divalent  lead  from  tetravalent.  Consequently  corre- 
sponding compounds  must  be  taken  for  comparison,  and 
this  too  greatly  increases  the  difficulties  of  classification. 
There  are  many  other  difficulties  which  we  cannot  discuss 
here. 

Many  other  plans  have  been  devised  for  exhibiting 
graphically  the  relations  thus  discovered  by  Newlands, 
Mendel£eff  and  Lothar  Meyer.  We  will  mention  here 
one,  shown  in  the  diagram  (Plate  7),  constructed  by 
Professor  Emerson  Reynolds  and  subsequently  modified 
by  Sir  William  Crookes.  Speaking  of  this,  Crookes,  in 
his  Presidential  Address  to  the  British  Association  in  1886, 
says: — 

"The  more  I  study  the  arrangement  of  this  zig-zag 
curve  the  more  I  am  convinced  that  he  who  grasps  the 
key  will  be  permitted  to  unlock  some  of  the  deepest 
mysteries  of  creation.  Let  us  imagine  if  it  is  possible  to 
get  a  glimpse  of  a  few  of  the  secrets  here  hidden.  Let 
us  picture  the  very  beginning  of  time,  before  geological 
ages,  before  the  earth  was  thrown  off  from  the  central 
nucleus  of  molten  fluid,  before  even  the  sun  himself  had 
consolidated  from  the  original  protyle.  Let  us  imagine 
that  in  this  primal  stage  all  was  an  ultragaseous  state,  at 
a  temperature  inconceivably  hotter  than  anything  now 
existing  in  the  visible  universe  ;  so  high  indeed,  that  the 
chemical  atoms  could  not  have  been  formed,  being  still 
far  above  their  dissociation  point.  In  so  far  as  protyle 
is  capable  of  radiating  or  reflecting  light,  this  vast  sea  of 
incandescent  mist,  to  an  astronomer  in  a  distant  star, 
might  have  appeared  as  a  nebula,  showing  in  the  spectro- 
scope a  few  isolated  lines,  or  forecasts  of  hydrogen, 
carbon,  and  nitrogen  spectra. 

"  But  in  the  course  of  time  some  process  akin  to  cooling, 
probably  internal,  reduces  the  temperature  of  the  cosmic 


Odd 

c  Series 


Paramagnetic. 


~~%*^-^ 


PLATE  7. — Reynolds-Crookes  diagram  of  atomic  weights. 


THE    MYSTERY    OF   THE   PERIODIC    LAW     131 

protyle  to  a  point  at  which  the  first  step  in  granulation 
takes  place  ;  matter  as  we  know  it  comes  into  existence, 
and  atoms  are  formed.  As  soon  as  an  atom  is  formed 
out  of  protyle  it  is  a  store  of  energy,  potential  (from  its 
tendency  to  coalesce  with  other  forms  of  atoms  by  gra- 
vitation or  chemically)  and  kinetic  (from  its  internal 
motions).  To  obtain  this  energy  the  neighbouring  pro- 
tyle must  be  refrigerated  by  it,  and  thereby  the  subse- 
quent formation  of  other  atoms  will  be  accelerated.  .  .  . 
The  easiest  formed  element,  the  one  most  nearly  allied 
to  the  protyle  in  simplicity,  is  first  born.  Hydrogen — 
or  shall  we  say  helium  ? — of  all  the  known  elements  the 
one  of  simplest  structure  and  lowest  atomic  weight,  is  the 
first  to  come  into  being.  For  some  time  hydrogen  would 
be  the  only  form  of  matter  (as  we  know  it)  in  existence, 
and  between  hydrogen  and  the  next  formed  element  there 
would  be  a  considerable  gap  in  time,  during  the  latter 
part  of  which  the  element  next  in  order  of  simplicity 
would  be  slowly  approaching  its  birthpoint.  Pending 
this  period  we  may  suppose  that  the  evolutionary  process 
which  soon  was  to  determine  the  birth  of  a  new  element 
would  also  determine  its  atomic  weight,  its  affini- 
ties, and  its  chemical  position.  In  the  original  genesis, 
the  longer  the  time  occupied  in  that  portion  of  the  cooling 
down  during  which  the  hardening  of  the  protyle  into 
atoms  took  place,  the  more  sharply  defined  would  be  the 
resulting  elements;  and,  on  the  other  hand,  with  more 
irregularity  in  the  original  cooling,  we  should  have  a 
nearer  approach  to  the  state  of  the  elemental  family  such 
as  we  know  it  at  present.  In  this  way  such  groups  as 
platinum,  osmium,  iridium  .  .  .  wefe  formed.  .  .  .  In  the  un- 
dulating curve  may  be  seen  the  action  of  two  forces,  one 
acting  in  the  direction  of  the  vectic  line,  and  the  other 
pulsating  backwards  and  forwards  like  a  pendulum. 
Assume  the  vertical  line  to  represent  temperature  slowly 


132     MODERN  CHEMISTRY  AND   ITS  WONDERS 

sinking  through  an  unknown  number  of  degrees,  from  the 
dissociation  point  of  the  first  known  element  down  to 
the  dissociation  point  of  those  last  shown  on  the  scale. 
But  what  form  of  energy  is  represented  by  the  oscillating 
line  ?  Swinging  to  and  fro  like  a  mighty  pendulum  to 
points  equidistant  from  a  neutral  centre  ;  the  divergence 
from  neutrality  conferring  atomicity  of  one,  two,  three, 
and  four  degrees  as  the  distance  from  the  centre  is  one, 
two,  three,  or  four  divisions  ;  and  the  approach  to  or 
retreat  from  the  neutral  line  deciding  the  electro-negative 
or  electro-positive  character  of  the  element — all  on  the 
retreating  half  of  the  swing  being  positive,  and  all  on 
the  approaching  half  being  negative  —  this  oscillating 
force  must  be  intimately  connected  with  the  imponder- 
able matter,  essence,  or  source  of  energy  we  call 
electricity." 

A  somewhat  similar  representation  of  the  Periodic 
Table  has  recently  been  put  forward  by  Soddy.1 

It  is  shown  in  Fig.  9,  and  represents  very  well  the 
probable  course  of  the  evolution  of  the  elements. 

The  periodic  system  is  far  from  perfect.  It  is  a 
generalisation  but  half  revealed,  whose  summit  is  hidden, 
so  to  speak,  in  the  clouds  and  whose  base  is  buried 
deep  in  the  underworld  of  Nature.  As  it  appears  to 
us,  it  is  only  the  result  of  a  chance  cross-section  taken 
at  ordinary  temperatures  and  pressures  through  the  vast 
body  of  chemical  facts.  It  is  only  when  we  have  taken 
this  section  at  all  temperatures  and  pressures,  have  studied 
each  set  of  compounds  produced  by  each  element  in  all 
theoretically  possible  levels  of  valency,  and  have  investi- 
gated the  influence  of  all  known  physical  influences  on 
the  properties  and  chemical  attractions  of  the  elements, 
that  we  will  obtain  a  true  notion  as  to  what  this  wonder- 
ful generalisation  really  signifies.  It  may  be  that  when 

1  The  Radio- Elements  and  the  Periodic  Law,  p.  11,  fig.  3,  1914  edition. 


THE    MYSTERY    OF    THE    PERIODIC    LAW     133 

52    ^    I 


134     MODERN   CHEMISTRY  AND   ITS  WONDERS 

this  is  done  the  most  wonderful  discoveries  will  roll  in 
upon  us,  and  that  we  shall  find  that  the  properties  pre- 
sented by  any  one  element  at  ordinary  temperatures  and 
pressures  are  only  particular  phases  or  conditions  which 
can  be  assumed  by  other  elements  under  other  and  as 
yet  unknown  conditions  (much  as  a  body  can  assume  the 
gaseous,  liquid,  or  solid  state  under  different  physical 
conditions).  We  cannot  at  present,  however,  tell.1 

1  The  author  has  carried  out  such  a  study  of  all  the  known  data  relating  to  the 
affinities  of  the  elements,  and  the  results  are  set  forth  in  his  work  Researches  on  the 
Affinities  of  the  Elements  (Churchill,  1905).  The  data,  however,  in  spite  of  the 
enormous  amount  of  work  spent  in  collecting  it,  is  still  far  too  incomplete  for  any 
great  generalisation  to  be  drawn  with  certainty.  Fifty  years  hence  matters  will 
be  very  otherwise,  and  the  time  will  then  be  ripe  for  another  effort. 

See  also  Geoffrey  Martin,  "  The  Chemical  Conditions  of  the  Elements," 
Chemical  News,  Nov.  10,  1905. 


CHAPTER    VI 

THE    RADIO-ELEMENTS    AND    THE    PERIODIC    LAW 

WITHIN  the  last  few  years  an  unexpected  light  has  been 
thrown  upon  the  Periodic  Law  and  the  complexity  of 
matter  by  recent  advances  in  the  subject  of  the  new  radio- 
active elements.1 

First  of  all,  however,  we  will  have  to  go  back  to  the 
subject  of  chemical  combination  and  valency.  It  is  well 
known  that  the  elements  differ  very  widely  in  their 
capacity  for  combining  with  other  atoms.  For  example, 
an  atom  of  the  element  chlorine  can  unite  with  only  one 
atom  of  hydrogen,  whereas  an  atom  of  oxygen  can  unite 
with  two,  an  atom  of  nitrogen  with  three,  an  atom  of 
carbon  with  four,  atoms  of  hydrogen,  and  so  on.  This  is 
seen  in  the  following  formulae  : — 


Cl-H          0/2          N-H 

Each  different  elementary  atom,  therefore,  possesses 
a  certain  combining  power  or  "  valency  "  as  chemists  call 
it.  It  can  only  combine  with  a  certain  fixed  and  limited 
number  of  other  atoms. 

If  an  atom  can  only  combine  with  one  atom  of  (say) 
hydrogen,  it  is  called  "  monovalent "  ;  if  only  with  two 
atoms  it  is  "  divalent,"  if  with  three  it  is  called  "  trivalent," 

1  The  subject  has  been  very  ably  discussed  by  Soddy  in  his  monograph, 
The  Radio- Elements  and  the  Periodic  Law  (Longmans,  Green,  1914). 

135 


136     MODERN   CHEMISTRY  AND   ITS  WONDERS 

and  so  on.  Thus  in  the  above  formula  Cl  is  monovalent, 
O  .is  divalent,  N  is  trivalent,  and  C  is  tetravalent. 

Now  for  a  long  time  past  it  has  been  thought  that  it 
is  the  presence  of  electrical  charges  on  the  atoms  which 
makes  them  unite  with  other  atoms. 

For  example,  on  referring  to  the  above  table,  it  will 
be  seen  that  the  carbon  atom  can  unite  with  four  atoms 
of  hydrogen  to  form  CH4.  Well,  chemists  explain  this 
by  saying  that  the  carbon  atom  has  attached  to  it  four 
negative  electrical  charges  (electrons  or  atoms  of  negative 
electricity),  thus :  C=,  while  the  hydrogen  atoms  are 
supposed  to  have  attached  to  them  a  positive  charge, 
thus,  -f  H. 

The  union  between  the  two  is  caused  by  the  powerful 
attraction  of  the  negative  charges  on  the  carbon  atom  for 
the  positive  charges  on  the  hydrogen  atoms,  thus : 

+  H  ±H 

p—      +H  ±H 

-      +H  U±H 

~      +H  ±H 

In  other  words,  chemical  union  is  due  to  electrical  forces 
emanating  from  atoms  (electrons)  of  negative  or  positive 
electricity  which  are  attached  to  the  surfaces  of  the  atoms. 
Each  unit  of  electricity  corresponds  to  a  unit  of 
"  valency." 

Moreover,  there  are  two  distinct  sorts  of  valencies, 
which  are  attached  to  the  same  atoms.  In  fact  there  is 
a  definite  rule,  first  published  by  Mendel6eff,  that  the 
total  sum  of  the  positive  and  negative  valencies  of  an 
element  amounts  to  eight.* 

Abegg 2    has    labelled    these    positive    and    negative 

1  The  matter  is  discussed  by  the  writer  in  the  Chemical  News,  1902,  86,  64, 
where  proof  of  the  universality  of  Mendeleeffs  generalisation  is  given. 
8  Abegg,  Zeitschr.  anorg.  Chern.,  1904,  39,  330. 


RADIO-ELEMENTS    AND    PERIODIC    LAW      137 

valencies  "  normal  valencies "  and  "  contra-valencies," 
the  "  normal  valencies "  being  those  which  predominate 
in  determining  the  chemical  behaviour  of  the  element, 
while  the  "  contra-valencies  "  are  those  which,  so  to  speak, 
take  rather  a  back  seat,  and  only  come  into  play  under 
certain  circumstances.  They  are  (t  latent  "  valencies. 

Now  seeing  that  the  valency  of  an  element  depends 
upon  the  number  of  electrical  charges  that  it  carries, 
and  that  the  radio-active  elements  throw  out  into  space 
both  positive  and  negative  electrical  charges,  it  is  obvious 
that  it  is  inherently  probable  that  there  would  be  some  con- 
nection between  the  subject  of  valency  and  radio-activity. 

The  first  suggestion  that  there  is  a  connection  between 
radio-activity  and  valency  was,  I  believe,  put  forward  by 
the  present  writer  so  long  ago  as  1901,1  when  the  subject 
of  radio-activity  was  in  its  infancy. 

In  these  communications  it  was  pointed  out  that  the 
radio-active  elements  are,  so  to  speak,  throwing  off 
positive  and  negative  valency  bonds,  so  that  a  change  of 
valency  must  result  with  each  electrical  charge  thrown 
out.  It  was  also  pointed  out  that  "  a  divalent  element  like 
radium,  by  the  simple  process  of  throwing  off  electrons 
(or  valency  bonds,  on  the  Helmholtz  theory  of  valency) 
is  producing  bodies  of  a  non-valent  nature,"  thereby  estab- 
lishing a  connection  between  valency  and  the  radio-activity. 

These  views  were  forgotten,  and  have  been  com- 
pletely overlooked  by  recent  '  writers  on  the  subject. 
Twelve  years  later,  however,  they  were  revived  and  ex- 
tended and  put  on  a  firm  experimental  basis  by  Fajans, 
Soddy,  Fleck,  Russel  and  other  workers.2 

1  Geoffrey  Martin,  "  Radio-activity  and  Atomic  Weight,"  Chemical  Neivs, 
1901,  83,  130;  "Valency  and  Radio-activity,"  Chemical  Neius,  1902,  85,  311. 
"  Radium  and  Helium,"  Chemical  News,  1904,  88,  147. 

2  K.    Fajans,    PhysikaL    Zeitsch.,     15th     February     1913,    14,     131-136. 
A.   Fleck,    Trans.    Chem.   Soc.,   1913,   103,   381   and    1052.      A.    S.    Russel, 
Chemical  News,  31st  January  1913,  107,  49. 


138     MODERN  CHEMISTRY   AND   ITS  WONDERS 

It  has  now  been  certainly  established  that  whenever 
a  radio-active  element  expels  a  beta  or  negative  ray — i.e. 
throws  out  one  negative  electrical  charge — it  reduces  its 
negative  valency  by  one  unit,  and  whenever  it  throws  off 
a  positive  or- alpha  ray  (which  carries  with  it  two  positive 
electrical  charges)  it  reduces  its  positive  valency  by  two 
units.  Let  us  take,  for  instance,  the  element  thorium,  Th. 
This  has  four  positive  valencies  and  so  gives  rise  to  com- 
pounds like  ThCl4. 

Now  the  thorium  atom  throws  off  an  alpha  ray  (two 
positive  charges)  and  so  its  positive  valency  becomes  re- 
duced from  -f  4  to  +2,  and  a  new  element,  Mesothorium  I, 
is  produced,  which  has  only  two  positive  valencies,  and 
so  produces  compounds  of  the  type  MX2,  where  X  stands 
for  a  non-metallic  element  like  chlorine. 

Again,  let  us  take  the  case  of  radium.  This  is  a 
divalent  element,  and  produces  compounds  like  RaCl2. 
Now  when  this  throws  off  an  alpha  ray  (two  positive 
charges)  its  positive  valency  is  reduced  by  two  and  so 
becomes  zero.  Consequently  a  non-valent  element,  the 
inactive  gas  Radium  Emanation,  is  produced.  In  conse- 
quence of  this  having  no  valency  it  will  not  unite  with 
other  atoms  and  so  is  far  more  chemically  inactive  than 
elements  like  nitrogen. 

The  same  rule  applies  for  every  positive  or  alpha  ray 
emitted  by  the  elements.  There  are  no  exceptions. 

In  exactly  the  same  way,  by  taking  specific  instances, 
it  was  proved  that  whenever  a  radio-active  element  throws 
out  a  beta  ray,  which  consists  of  a  single  negative  elec- 
trical charge,  it  reduces  its  negative  valency  by  one,  and  this 
rule  also  seems  to  hold  without  any  exception. 

Now  there  is  a  very  obvious  connection  between 
the  position  of  an  element  in  the  Periodic  System  and 
the  number  of  positive  or  negative  valencies  that  it 
exerts. 


RADIO-ELEMENTS    AND    PERIODIC    LAW     139 

This  is  best  seen  by  taking  the  elements  of  a  series 
of  the  Periodic  Table,  thus  : — 

PERIODIC  TABLE 


GROUP 

GROUP!  GROUP 

GROUP 

GROUP 

GROUP  GROUP 

GROUP 

'• 

II.    1    III. 

IV. 

V. 

VI.           VII. 

VIII. 

Na. 

Mg.    !    Al. 

Si. 

P. 

s.    !  ci. 

Ar. 

Positive  Valencies  . 

+  1 

+  2    i    +3 

+  4 

+  5 

+  6    !    +7 

+  8 

Negative  Valencies 

-7 

-6        -5 

-4 

-3 

-2    i     -1 

0 

Total  number  of  V      Q 
Valencies            / 

8           8 

8 

8 

8           8 

I 

8 

For  example,  elements  belonging  to  Group  I  have 
one  positive  and  seven  negative  valencies  (total  eight 
valencies) ;  and  elements  belonging  to  Group  II  have 
two  positive  and  six  negative  valencies  (total  eight),  and 
so  on  right  up  the  series. 

So  that  if  we  alter  the  fundamental  valencies  of  an 
element  we  alter  its  position  in  the  Periodic  System.  For 
example,  in  the  case  of  the  element  silicon  (see  above 
table,  Si,  Group  IV),  which  has  four  positive  valencies,  if 
we  made  it  expel  two  positive  valencies  (an  alpha  ray),  it 
would  have  only  two  positive  valencies  left  and  we  would 
shift  it  from  Group  IV  to  Group  II,  for  as  will  be  seen  the 
elements  of  this  latter  group  have  two  positive  valencies. 

If,  on  the  other  hand,  we  made  silicon  expel  a  beta 
ray  or  negative  valency,  we  would  shift  silicon  into  Group 
V  (phosphorus  group)  because  the  elements  of  these 
groups  only  exhibit  three  negative  valencies. 

Hence  we  can  draw  up  the  following  rule,  which  was 
first  clearly  enunciated  by  Fajans  (loc.  cit.)  and  which 
has  been  firmly  established  by  the  brilliant  research  work 
of  Soddy,  Fleck,  Russel  and  others  : — 

Whenever  a  radio-active  element  expels  an  alpha  ray  (two 
positive  charges)  we  cause  it  to  shift  its  position  in  the  Periodic 


140     MODERN   CHEMISTRY  AND   ITS  WONDERS 

Table  by  two  places  from  right  to  left  in  the  direction  of  dim- 
inishing mass.  When,  however,  the  element  expels  a  beta  ray 
(a  single  negative  charge),  it  shifts  its  position  in  the  Periodic 
Table  by  one  place  only,  but  in  the  opposite  direction  to  that  for 
the  alpha-ray  change. 

This,  then,  is  the  first  great  generalisation  made  as 
regards  the  radio-active  elements  and  the  Periodic  System 
and  throws  light  on  a  whole  array  of  complex  questions, 
as  will  be  presently  seen. 

The  second  important  generalisation  is  this  :  The  mass 
of  an  alpha  particle  (which  seems  to  be  a  helium  atom)  is 
about  four  times  that  of  an  atom  of  hydrogen.  So  that 
whenever  a  radio-active  element  expels  an  alpha  particle,  it  reduces 
its  atomic  weight  by  four.  For  example,  radium,  atomic 
weight  226,  expels  an  alpha  particle  and  gives  rise  to  a 
new  element  known  as  "  Radium  Emanation " — a  gas. 
This  necessarily  has  an  atomic  weight  of  226  —  4=222. 

On  the  other  hand,  when  a  beta  particle  is  expelled 
the  atomic  weight  does  not  noticeably  change,  because 
the  mass  of  a  beta  particle  is  less  than  y^j^th  part  of 
that  of  a  hydrogen  atom. 

Hence,  knowing  the  radiations  sent  forth  by  a  radio- 
active element,  we  can  trace  both  the  change  in  position 
which  the  products  assume  in  the  periodic  table,  and 
also  the  change  in  their  atomic  weight.  In  other  words, 
we  can  follow  accurately  the  wandering  of  the  position 
of  the  successive  products  of  radio-active  change  across 
the  face  of  the  periodic  system. 

The  following  table,  taken  from  Soddy's  Radio-Elements 
and  the  Periodic  Law,  p.  3,  shows  how  the  position  of  all 
the  thirty-four  known  radio-active  elements  have  been 
placed  in  the  periodic  table. 

The  last  and  third  principle,  brought  to  light  by 
Soddy,  Fleck,  and  Russel,  is  perhaps  the  most  surprising 
of  all,  and  reveals  an  unsuspected  complexity  of  matter  ; 


RADIO-ELEMENTS    AND    PERIODIC    LAW     141 


s&vw  OIUO.LV  jo  sum 


142      MODERN  CHEMISTRY  AND   ITS  WONDERS 

at  the  same  time  it  throws  a  gleam  of  light  into  the 
obscure  depths  of  the  Periodic  System,  and  explains  many 
of  its  perplexing  "exceptions."  This  principle  may  be 
explained  as  follows  : 

We  have  previously  stated  that  there  are  about  thirty- 
four  new  radio-elements  now  known  (1914).  It  is  found, 
however,  that  they  have  not  all  different  properties. 
Nearly  every  radio-element  betrays  a  striking  chemical  resem- 
blance to  some  other  known  chemical  element,  the  resemblance 
being  so  close  that  they  cannot  be  separated  from  each  other  by 
ordinary  chemical  methods;  in  fact  the  properties  of  a  radio- 
active element  approaches  so  closely  to  those  of  its 
chemical  analogue  that  they  can  be  "  accurately  described 
in  a  single  sentence "  as  those  of  its  analogue.  The 
chemistry,  therefore,  of  the  radio-elements  becomes  the 
chemistry  of  a  much  smaller  number — about  ten  in  all — 
of  types  of  elements  (Soddy). 

For  example  it  will  be  seen  from  the  table  given  here,1 
that  radium  B,  actinium  B,  and  thorium  B  are  all  de- 
scribed as  quite  similar  in  chemical  properties  to  lead  : 

THE  URANIUM  SERIES 


COMMON  BODY 

NAME  OF  ELEMENT. 

SYMBOL. 

RADIATION 
EMITTED. 

POSSESSING  CHEMICAL 
PROPERTIES  MOST 

SIMILAR. 

Uranium  1  . 

Url 

a 

Uranium 

Uranium  X  . 

Uranium  X2 

UrXx 
UrX2 

ft  7 
ft  7 

Thorium 
Tantalum 

Uranium  2  . 

Ur2 

a 

Uranium 

Ionium 

lo 

a 

Thorium 

Radium 

Ra 

a,  |8 

Radium 

Radium  emanation 
Radium  A    . 

RaEm 
RaA 

a 
a 

(Inert  gas) 
Tellurium 

Radium  B    . 

RaB 

ft  7 

Lead 

Radium  C    . 

RaC 

«,  ft  7 

Bismuth 

Radium  D    . 

RaD 

ft  7 

Lead 

Radium  E    . 

RaE 

ft 

Bismuth 

Polonium 

Po 

a 

Tellurium 

1  Obtained  from  Dr.  A.  S.  Russel. 


RADIO-ELEMENTS    AND    PERIODIC    LAW     143 

THE  ACTINIUM  SERIES 


COMMON   BODY 

NAME  OF   ELEMENT. 

SYMBOL. 

RADIATION 
EMITTED. 

POSSESSING  CHEMICAL 
PROPERTIES   MOST 

SIMILAR. 

Actinium 

Act 

None 

Lanthanum 

Radio-actinium     . 

RaAct 

a,  P,7 

Thorium 

Actinium  X 

ActX 

a 

Radium 

Actinium  emanation 

ActEm 

a 

Radium  emanation 

Actinium  A 

ActA 

a 

Tellurium 

Actinium  B 

ActB 

ft 

Lead 

Actinium  C 

ActC 

a 

Bismuth 

Actinium  D 

ActD 

0,7 

Thallium 

THE  THORIUM  SERIES 


COMMON   BODY 

NAME   OF   ELEMENT. 

SYMBOL. 

RADIATION 
EMITTED. 

POSSESSING  CHEMICAL 
PROPERTIES  MOST 

SIMILAR. 

Thorium       .         . 

Th 

a 

Thorium 

Mesothorium  1 

Msthl 

None 

Radium 

Mesothorium  2     . 

Msth2 

0,7 

/Actinium  and 
\     Lanthanum 

Radiothorium 

Rath 

a 

Thorium 

Thorium  X  . 

ThX 

«,/3 

Radium 

Thorium  emanation 

ThEm 

a 

Radium  emanation 

Thorium  A  . 

ThA 

a 

Tellurium 

Thorium  B  . 

ThB 

ft  7 

Lead 

Thorium  C  . 

ThC 

a,  0,7 

Bismuth 

Thorium  D  . 

ThD 

ft  7 

Thallium 

This  property  of  radio-elements  of  being  so  similar 
in  chemical  properties  to  common  elements,  although 
one  of  the  most  extraordinary  phenomena  in  the  subject, 
greatly  simplifies  chemical  work  with  the  raidio-elements. 
Thorium  B,  for  example,  is  so  similar  to  lead  that  there 
is  no  known  method  of  separating  one  from  the  other. 
Any  reagent  which  precipitates  the  one  also  precipitates 
the  other.  In  order,  therefore,  to  separate  thorium  B 


i44     MODERN   CHEMISTRY  AND  ITS  WONDERS 

from  other  radio-elements,  all  we  have  to  do  is  to  add 
a  trace  of  lead  to  the  radio-active  solution,  and  then 
separate  lead  by  ordinary  analytical  methods. 

It  will  be  found  that  the  thorium  B  is  separated 
quantitatively  with  it,  and  is  free  from  all  other  radio- 
elements  except  those  which  have  the  same  chemical 
properties  of  lead,  or  which  have  been  generated  from 
the  thorium  B  during  the  time  of  separation  to  the 
time  of  examination.  • 

We  have  explained  on  p.  140  how  the  radio-elements 
change  their  atomic  weights  and  their  chemical  positions 
in  the  Periodic  system,  and  a  study  of  Soddy's  table  on 
p.  141  shows  very  clearly  how  one  or  more  radio-elements 
can  come  to  occupy  the  same  position  as  other  elements 
in  the  Periodic  System.  But  the  curious  fact  brought 
to  light  by  this  new  line  of  research  is  that  several  elements 
can  occupy  the  same  position  in  the  periodic  system  and  can  all 
exhibit  exactly  the  same  chemical  and  physical  properties,  and  be 
chemically  non-separable,  and  yet  not  be  identical  with  each  other. 

Soddy  calls  such  chemically  similar  elements  "isotopes." 
//  does  not  matter  in  the  least  whether  they  have  the  same  atomic 
mass.  Elements  of  quite  different  atomic  weights  can  have  the 
same  chemical  properties,  and  occupy  the  same  position  in  the 
Periodic  System. 

Indeed  this  has  recently  been  proved  in  the  case 
of  lead.  For  example,  by  looking  at  Soddy's  table  on 
p.  141  the  reader  will  see  that  the  end  products  of  all 
the  known  disintegrating  series  fall  into  the  place  in 
the  Periodic  Table  occupied  by  lead. 

According  as  these  end  products  are  derived  from 
thorium  or  "from  uranium,  their  atomic  weights  should 
be  different.  Thus  the  atomic  weight  of  the  thorium 
isotope  should  be  206  and  that  of  the  uranium  isotope 
should  be  208*4.  Experiments  carried  out  on  the  atomic 
weights  of  lead  from  different  sources  vary  from  206-4 


RADIO-ELEMENTS    AND    PERIODIC    LAW     145 

to  207-15 — and  yet  all  these  samples  of  lead  are  chemically 
and  physically  identical.  (See  Annual  Reports  on  the  Pro- 
gress of  Chemistry  for  1914,  p.  37.) 

Hence  it  is  not  the  atomic  weight  which  plays  the 
predominating  part  in  deciding  the  chemical  properties 
of  the  elements.  It  is  the  chemical  forces  it  exerts,1 
which  in  turn  depend  upon  the  electrical  contents  of 
the  atom.  The  Periodic  Law  thus  expresses  the  chemi- 
cal nature  of  matter  as  a  function  of  two  variables, 
namely  the  atomic  mass  (weight)  and  the  electrical  con- 
tent. It  is  the  atomic  mass  which  is  the  predominant 
variable  in  the  vertical  columns  of  the  periodic  table, 
because  the  mass  varies  in  the  vertical  columns  by  large 
steps  between  the  various  members  of  the  same  families 
of  elements,  whose  members  are  not  identical  in  properties. 
In  the  horizontal  rows  of  the  periodic  table,  however, 
it  is  the  electrical  content  which  decides  the  chemical 
properties,  such  as  valency,  chemical  affinity  and  so  on, 
and  so  here  it  is  the  electrical  content  which  is  the 
predominant  variable. 

Professor  Soddy  (Radio- Elements  and  the  Periodic  Law, 
p.  7)  also  comes  to  the  conclusion  that  different  elements 
occupying  the  same  place  in  the  Periodic  Table  are  in- 
distinguishable in  spectra  and  other  physical  properties. 
He  explains  this  by  the  circumstance  that  the  spectra, 
in  all  probability,  originates  from  the  movements  of  only 
very  few  electrons  in  their  orbits  in  an  outer  ring  around 
the  atoms,  the  same  few  electrons  conditioning  chemical 
valency  and  affinity  and  also  the  great  majority  of  the 
physical  properties  as  well.2 

1  This  was  pointed  out  in  1905  by  the  author  in  his  book,  Researches  on  the 
Affinities  of  the  Elements. 

2  It  is  very  interesting  to  note  that  this  new  work  on  radio-activity  very 
strikingly  confirms  the  conclusions  published  in  1905  in  my  book,  Researches  on 
the  Affinities  of  the  Elements  and  the   Causes  of  the  Chemical  Similarity  or 
Dissimilarity  of  Elements  and  Compounds  (London,  J.  &  A.  Churchill).     Here 

K 


146     MODERN   CHEMISTRY  AND   ITS  WONDERS 

What  is  the  explanation  of  the  Periodic  Law,  this 
mighty  generalisation  which  is  written  across  the  whole 
domain  of  inorganic  chemistry  ?  We  do  not  know.  An  ex- 
planation involves  the  answer  to  two  different  questions  : — 

1.  Why  do  the  atomic  weights  increase  as  they  do  in 
such   an   irregular  manner  from   element  to   element,  a 
difference  varying  from   one   to   three  units,  and  conse- 
quently representing  a  weight  varying  from  that  of  2000 
to  6000  electrons  ?     No  clear  explanation  of  this  has  ever 
been   given,   but   Soddy's  work  on  radio-active  elements 
seems  to  give  the  correct  solution. 

2.  Why  does  the  addition  of  a  certain  atomic  mass 
cause  a  periodic  recurrence  of  similar  properties  ? 

This  involves  the  further  question  what  do  we  mean 
by  chemical  similarity  ?  What  is  the  cause  of  it  ?  I 
think  that  it  was  Wilhelm  Ostwald  (Allge.  Chemie,  vol.  i. 
p.  138,  2nd  Ed.  1903)  who  first  clearly  stated  that  the 
notion  of  the  chemical  similarity  of  the  elements  was 
much  too  vague,  up  to  date,  to  allow  it  to  be  applied 
with  sharpness  in  fixing  the  position  of  an  element. 
The  present  writer,  as  the  result  of  a  very  elaborate 
investigation  of  what  underlies  the  notion  of  chemical 
similarity,  discovered  how  to  deduce  a  numerical  value 
for  it.  He  first  showed1  that  chemically  similar  elements 

it  is  proved  :  (1)  That  the  electrical  forces  (chemical  attractions  or  affinities) 
which  the  different  elementary  atoms  exert  completely  decide  the  chemical 
nature  of  the  elements,  the  atomic  mass  having  only  quite  a  subsidiary  influence. 

(2)  That  the   same  factors  which   govern  the  chemical  properties  of   the 
elements  also  govern  their  physical  properties  as  well,  so  that  chemically  similar 
bodies  necessarily  must  be  physically  similar  as  well. 

(3)  That  the  cause  of  the  Chemical  Similarity  of  the  elements  is  due  to  the 
fact  that  they  exert  proportional  (not  equal)  chemical  forces. 

(4)  By  altering  the  chemical  forces  an  element  exerts,  we  can  make  it  take 
on  the  properties  of  other  elements.     So  that  two  different  kinds  of  matter  atoms 
would  be  chemically  and  physically  similar  in  properties  if  we  could  make  them 
exert  the  same  forces.     It  is  not  the  nature  of  the  matter  which  counts,  it  is 
the  nature  of  the  forces  it  exerts. 

1  Martin,  Researches  on  the  Affinities  of  the  Elements,  pp.  40-56. 


RADIO-ELEMENTS    AND    PERIODIC    LAW      147 

exert  proportional  affinities  (chemical  attractions)  on  other 
atoms. 

For  example,  if  we  compare  the  affinities  which  sodium 
or  potassium  exert  on  other  elements,  we  shall  find  that 
in  general  when  sodium  exerts  a  weak  affinity  potassium 
does  the  same,  and  where  sodium  exerts  a  strong  affinity 
potassium  also  exerts  a  strong  affinity.  So  that  the  sodium 
atom  may  replace  the  potassium  atom  in  any  reaction 
without  altering  the  way  the  reaction  proceeds — sodium 
carrying  out  the  same  reactions  as  potassium  but  somewhat 
more  feebly.  And  so  it  is  also  with  fluorine  and  chlorine — 
fluorine  carrying  out  the  same  reactions  as  chlorine,  but 
more  strongly.  In  other  words,  an  atom  or  radicle  is 
chemically  similar  to  another  when  and  only  when  its  affinities 
are  proportional  to  those  of  the  other.  The  more  nearly  equal 
each  to  each  are  these  affinities  the  two  elements  exert,  the 
more  alike  are  they  chemically.  When  in  addition  to  this 
it  is  found  that  the  absolute  magnitude  of  the  forces  or 
affinities  that  an  element  exerts  on  other  atoms  com- 
pletely determines  both  its  chemical  and  its  physical 
properties,1  we  at  last  arrive  at  a  clear  idea  of  what 
has  to  be  done  in  order  to  explain  the  periodic  system. 
It  is  this : — We  have  only  to  explain  why  each  atom 
attracts  all  the  other  atoms  with  the  exact  numerical  values 
that  it  is  known  to  exert.  From  this  will  follow  the 
whole  explanation  of  the  periodic  system.  The  matter 
therefore  resolves  itself  into  an  investigation  of  the  nature 
of  chemical  force,  and  since  the  forces  are  probably 
electrical  in  nature,  the  ultimate  solution  of  the  problem 
is  taken  altogether  out  of  the  hand  of  the  chemist  and 
placed  in  the  hand  of  the  physicist.  It  is,  therefore,  not 
without  significance  to  find  that  recently  the  most  in- 
teresting and  notable  attempts  to  elucidate  the  mystery  of 
the  periodic  law  have  come  from  physicists.  In  particular 

1  Martin,  opus  tit.,  pp.  10-17,  123. 


148     MODERN   CHEMISTRY  AND   ITS  WONDERS 

Professor  ].  J.  Thomson,  of  Cambridge,  has  made  a  most 
interesting  attempt  to  account  for  the  periodicity  of  pro- 
perties by  supposing  that  the  elements  are  built  up  of 
successive  rings  of  electrons.1 

His  system,  however,  suffers  from  serious  defects, 
which  have  been  discussed  by  Arrhenius  in  his  recent 
Theories  of  Chemistry  (1907),  pp.  93-102.  But  even 
accepting  it  as  it  stands  we  cannot  say  that  the  problem 
has  been  in  any  way  solved,  until  this  theory  has  been 
shown  to  explain  accurately  the  magnitude  of  the  attrac- 
tions exerted  by  the  different  atoms  on  each  other,  and 
this  at  present  it  makes  no  attempt  to  do. 

In  the  present  writer's  opinion  what  is  wanted  at 
present  are  actual  measurements  of  the  affinities  of  all 
the  elements.  Not  until  we  know  these  constants, 
and  we  shall  some  day  know  them,  can  we  devise  a 
proper  theory  numerically  to  fit  them.  And  we  must 
know  these  constants  not  only  for  one  valency  level 
entered  on  by  the  element,  but  for  all  valency  levels 
which  can  be  assumed  by  it.  When  this  is  done,  and  it 
is  a  matter  of  hard  experimenting,  we  can  then,  and  not 
before,  attempt  to  build  up  a  theory  of  the  atoms  which 
will  account  for  the  magnitudes  of  the  forces  that  they 
exert  upon  each  other,  and  thus  at  a  single  blow  explain 
the  whole  of  that  great  generalisation  which  has  for  so 
long  loomed  so  largely  in  the  chemical  world.  And 
since  we  ourselves,  our  bodies,  and  all  the  material 
universe  about  us,  are  built  up  of  these  very  same  atoms 
which  are  joined  together  by  this  great  generalisation, 
who  knows  but  that  the  solution  of  this  grand  mystery 
will  bring  us  nearer  to  the  elucidation  of  other  mysteries 
which  have  for  ages  baffled  the  intellect  of  man  ?  Then, 
indeed,  we  can  take  up  with  a  new  courage  the  investiga- 
tion of  that  grand  problem,  the  nature  of  life  itself.  We 

1  J.  J.  Thomson,  Phil.  Mag.  (6),  1906,  11,  769,  and  previously. 


RADIO-ELEMENTS    AND    PERIODIC    LAW      149 

agree  with  H.  G.  Wells  when  he  says,1  "  It  is  possible  to 
believe  that  all  the  past  is  at  the  beginning  of  a  beginning, 
and  that  all  that  is  and  has  been  is  but  the  twilight  of  the 
dawn,  It  is  possible  to  believe  that  all  that  the  human 
mind  has  ever  accomplished  is  but  the  dream  before  the 
awakening." 

And  now,  having  brought  the  reader  to  the  very 
portals  of  the  unknown,  and  having  bade  him  look  fear- 
lessly into  one  of  the  great  mysteries  of  the  universe 
whose  complete  elucidation  we  may  confidently  leave  to 
the  future,  we  must  here  cry  halt  and  take  our  leave. 

1  The  Discovery  of  the  Future. 


CHAPTER    VII 
MODERN     ALCHEMY 

IT  has  been  the  immemorial  dream  of  the  chemists 
of  the  east  that  the  elements  can  be  transmuted  one  into 
the  other,  and  that  he  who  possessed  the  secret  could  at 
will  change  a  comparatively  worthless  metal  like  lead 
into  a  valuable  metal  like  gold,  and  so  amass  for  himself 
wealth  beyond  the  dreams  of  avarice. 

An  incredible  amount  of  experimental  work  was 
expended  on  this  object  by  the  alchemists,  and  out  of 
their  labours  the  science  of  modern  chemistry  has  arisen. 
The  alchemists,  however,  did  not  succeed  in  their  quest. 
It  has  been  clearly  demonstrated  that  in  all  cases  where 
superficially  there  seemed  some  reason  to  believe  a  trans- 
mutation had  been  effected,  the  fact  was  in  truth  not 
so  ;  either  the  materials  were  impure,  or  the  resulting 
products  merely  looked  like  the  body  to  be  produced, 
but  were  not  identical  with  it. 

At  the  beginning  of  the  twentieth  century,  then,  it 
was  firmly  established  as  a  fundamental  dogma  of 
chemical  science  that  no  one  element  can  be  transformed 
into  another.  The  eighty  or  ninety  odd  elements  known 
were  regarded  as  the  eternal  and  unchangeable  forms  of 
matter  out  of  which  the  whole  material  universe  was 
fashioned.  Each  element  was  thus  placed  in  a  sort  of 
watertight  compartment  by  itself  ;  it  had  absolutely  no 
connection  with  any  other  element,  no  common  basis  or 
constituent,  but  stood  unique  in  solitary  isolation. 

But  in  1898  radium  was  discovered,  and  with  it 

150 


MODERN    ALCHEMY  151 

a  whole  series  of  puzzling  phenomena.  Soon  it  was 
proved  beyond  doubt  that  not  only  this  element  but 
others  as  well  were  decomposing  and  giving  rise  in  the 
act  of  decomposition  to  helium  and  other  elementary 
substances.  The  elements,  so  far  from  being  the  immut- 
able foundation  stones  of  the  material  universe,  were  seen 
to  be  in  the  throes  of  incessant  and  spontaneous  change, 
evolving  and  devolving  into  other  forms  of  matter  in  a 
most  complex  way.  A  shock  was  dealt  to  the  smug  and 
self-satisfied  attitude  of  the  chemical  world  at  that  time. 
The  enormous  superstructure  of  chemical  facts  and  theories, 
which  seemed  so  well  established  by  such  immense  labour, 
revealed  unsuspected  weaknesses  and  flaws  in  its  deep- 
laid  foundations  such  as  might  bring  the  whole  to  utter 
ruin.  Fierce  ridicule  and  scorn  were  poured  forth  on 
those  who  sought  to  upset  the  stability  of  the  chemical 
world,  and  indeed  the  present  writer  well  remembers  the 
open  ridicule  to  which  he  was  subjected  when  he  in  1902 
first  put  forward  the  idea  that  the  radio-active  elements 
are  decomposing  elements  (see  page  91).  However,  the 
brilliant  experimental  work  of  the  Curies,  Rutherford, 
Soddy,  Ramsay  and  others  has  finally  led  to  the  establish- 
ment of  the  great  fact  that  certain  elements  do  most 
undoubtedly  spontaneously  decompose,  and  in  doing  so 
liberate  enormous  quantities  of  energy. 

However,  up  to  the  present  no  man  has  succeeded 
in  controlling  the  unknown  irresistible  forces  inherent 
in  the  matter  atoms  themselves,  which  causes  them  un- 
ceasingly to  evolve  and  devolve  into  other  atomic  forms 
of  matter.  Radio-activity,  in  fact,  seems  to  be  one  of 
the  least  controllable  of  natural  forces.  Neither  heat 
nor  cold,  chemical  nor  mechanical  forces  affect  the 
process  in  the  least.  Up  to  the  present  Nature  has  kept 
control,  while  man  has  looked  on  with  hungry  eyes, 
knowing  that  could  he  but  dominate  such  gigantic  forces, 


152     MODERN  CHEMISTRY  AND   ITS  WONDERS 

accelerate  or  retard  them  to  his  convenience;  he  could 
revolutionise  the  whole  surface  of  our  planet  and  supply 
unlimited  power  to  solve  its  industrial  problems.  But 
at  last  man  has  begun  the  long  delayed  attack  on  Nature's 
secret  fortress.  The  first  experiments  to  obtain  control 
of  these  vast  natural  forces  and  transmute  at  man's  will 
one  element  into  another,  were  carried  out  by  that  bold 
and  original  experimenter,  Sir  William  Ramsay. 

If  on  the  earth  experiment  shows  that  the  elements 
are  breaking  down  into  lighter  and  lighter  atoms,  and  so 
are  vanishing,  surely  in  other  regions  of  space  matter 
must  be  forming,  lighter  elements  must  be  condensing 
into  heavier  ones  ?  Otherwise  the  whole  world  and  the 
universe  itself  in  a  few  billion  years  would  rush  into 
oblivion. 

Crookes  and  Lockyer  long  ago  conjectured  that  in 
the  nebula  and  the  great  waste  celestial  spaces,  the 
lighter  elements  condense  to  heavier,  and  matter,  so  far 
from  vanishing,  is  there  being  created.  Ramsay  asked 
himself,  what  are  the  conditions  which  regulate  this 
growth  and  decay  of  matter,  this  transmutation  of  the 
elements  ?  If  stupendous  forces  are  evolved  when  the 
atoms  decompose,  tremendous  forces,  so  Ramsay  argued, 
must  be  brought  into  play  to  form  them  again,  Ramsay 
cast  around  to  apply  stupendous  forces  to  these  atoms, 
and  hit  upon  the  expedient  of  employing  exploding 
radium  atoms.  When  radium  atoms  explode  we  have 
seen  (see  page  93)  that  masses  of  matter  and  electrons 
are  hurled  forth  with  velocities  of  thousands  of  miles  a 
second.  Ramsay  conjectured  that  the  terrific  shock  of 
collision  with  these  flying  particles  would  succeed  in 
shattering  quite  stable  atoms,  such  as  those  of  copper, 
and  produce  from  them  lighter  elements  like  lithium, 
sodium  or  hydrogen.  So  Ramsay  and  his  pupils  made 
the  experiment.  They  showed  that  if  a  solution  of  the 


MODERN    ALCHEMY  153 

radium  emanation  in  water  be  left  to  change,  one  of  the 
products  is  the  element  neon.  A  solution  in  which  copper 
sulphate  is  present,  however,  yields  another  element — 
argon,  and  a  trace  of  lithium.  Whether  this  latter  element 
came  from  the  glass  or  not,  or  whether  it  had  actually 
been  produced  as  a  product  of  atomic  breakdown 
remains  at  present  undecided.  Other  remarkable  ex- 
periments in  which  carbon,  oxygen  and  other  elements 
have  been  produced  in  traces  have  also  been  described. 
If  these  experiments  are  confirmed  it  would  seem  that 
radium  is  capable  of  producing  at  ordinary  temperatures 
the  same  effect  that  is  brought  about  by  the  transcendental 
temperatures  reigning  in  some  stars.  For  there  is  now 
little  doubt  that  on  these  the  formation  of  elements  one 
from  the  other  is  swiftly  proceeding  on  an  enormous 
scale. 

As  a  matter  of  fact,  however,  these  experiments  have 
not  been  confirmed  up  to  the  time  of  writing.  The 
alleged  transmutation  of  copper  into  lithium  and  sodium 
by  A.  T.  Cameron  and  W.  Ramsay  in  1908  was  denied 
in  the  same  year  by  S.  Curie  and  Gledisch  and  also  by 
E.  P.  Perman  ;  also  the  production  of  neon  from  radium 
emanation  by  W.  Ramsay  (1907)  and  Ramsay  and 
Cameron  (1908)  has  been  denied  by  E.  Rutherford  and 
T.  Royds  (1908).  These  transmutations,  therefore,  could 
not  be  confirmed  by  other  workers  and  at  present  the 
chemical  world  regards  them  with  doubt.  However  the 
reader  must  remember  that  Sir  William  Ramsay  is 
probably  one  of  the  most  skilful  experimentalists  that  the 
world  has  ever  seen,  and  when  we  read  with  astonishment 
of  complicated  experimental  processes  being  carried  out 
by  Sir  William  Ramsay  and  his  co-workers  on  a  volume 
of  gas  not  exceeding  a  few  hundredths  of  a  cubic  milli- 
metre— a  volume  smaller  than  that  of  a  small  pin's  head  ; 
our  wonder  is  not  that  his  results  have  not  been  con- 


154     MODERN  CHEMISTRY  AND  ITS  WONDERS 

firmed, 'but  that  the  experiments  could  have  been  carried 
out  at  all. 

Sir  W.  Ramsay  thinks  that  dry  hydrogen  becomes 
polymerised  into  helium  when  subjected  to  the  action  of 
cathode  rays  in  a  vacuum  tube,  while  for  the  production 
of  neon  the  presence  of  oxygen  is  necessary, — the  oxygen 
being  derived  from  a  trace  of  moisture  or  from  the  bom- 
bardment of  the  glass  by  the  rays.  Ramsay  modified  the 
experiment  by  placing  dry  hydrogen  in  a  vacuum  tube 
and  passing  an  electrical  discharge  for  5-6  hours  between 
an  aluminium  cathode  and  an  anode,  which  were  coated 
with  sulphur.  He  found  that  argon  was  produced. 
When  the  electrodes  were  coated  with  selenium  instead 
of  sulphur  krypton  was  produced.  Consequently  the 
three  elements,  neon,  argon,  and  krypton,  elements  all 
in  one  group  of  the  periodic  table,  and  whose  atomic 
weights  are  in  ascending  scale,  have  thus,  apparently, 
been  produced  from  hydrogen  in  the  presence  of  oxygen, 
sulphur  and  selenium — also  elements  of  one  group  of  the 
periodic  table  with  atomic  weights  in  ascending  scale. 

The  subject  entered  a  new  phase  in  1913,  for  in  that 
year  Collie,  Patterson  and  Masson  began  to  publish  their 
researches. 

Ramsay,  it  will  be  recollected,  used  radium  as  his 
source  of  bombarding  particles.  Cathode  rays  (the  rays 
evolved  by  connecting  a  very  highly  exhausted  vacuum 
tube  with  a  high  potential  induction  coil),  however,  also 
consist  of  a  stream  of  the  same  swiftly  flying  particles. 
The  cathode  rays,  in  fact,  are  supposed  to  be  identical 
with  the  beta  rays  expelled  by  radium,  and  consist  of  a 
stream  of  negatively  charged  particles,  each  of  about 
TT^j-  of  the  mass  of  a  hydrogen  atom,  and  fly  with  the 
velocity  of  about  180,000  miles  a  second.  Why  not, 
therefore,  bombard  stable  elements  with  these  projectiles, 
and  see  whether  the  shock  of  this  cannonade  would 


MODERN    ALCHEMY  155 

shatter  their  atoms  and  produce  from  their  ruins  other 
kinds  of  elements  ?  Radium  is  expensive,  but  cathode 
rays  are  easy  to  produce  and  are  within  the  means  of 
every  chemical  or  physical  laboratory. 

So  in  1913  Collie  and  Patterson1  placed  some  pure 
calcium  fluoride,  CaF2,  in  a  cathode  tube  and  subjected  it 
to  the  bombardment  by  cathode  rays.  Now  calcium 
fluoride  is  composed  of  two  elements  only — calcium  and 
fluorine.  Yet  after  a  time  gases  were  found  to  be  evolved 
in  the  tube,  gases  composed  of  oxygen,  hydrogen,  carbon 
monoxide  (CO,  p.  210)  and  a  small  amount  of  a  new 
element  called  neon.  In  other  words,  new  elements  made 
their  appearance  in  the  tube — elements  which  were  not 
present  in  the  substance  bombarded.  Whence  have  they 
come  ?  Have  they  been  derived  by  the  smashing  up  of  the 
calcium  and  fluorine  atoms  by  the  vigorous  bombardment  ? 
Collie  and  Patterson  think  so. 

Next  they  tried  placing  a  little  bit  of  glass  wool  in  the 
tube,  and  from  this  there  was  evolved  considerable 
amounts  of  the  element,  neon.  Many  other  similar  ex- 
periments were  made,  and  nearly  all  the  substances  bom- 
barded were  found  to  yield  traces  of  elements  which 
originally  were  not  present  in  them.  It  looks,  in  fact,  as 
if  the  problem  of  the  alchemists  had  in  part  been  solved, 
and  that  one  element  had  been  turned  into  another. 

But  now  a  fierce  controversy  broke  out.  Other 
workers  tried  to  repeat  these  experiments  and  failed. 
Sir  ].  J.  Thomson 2  came  to  the  conclusion  that  the 
evolved  neon  came  from  the  electrodes,  while  other 
workers  suggested  that  it  had  leaked  in  from  outside. 

Collie  and  his  co-workers,  however,  took  these  objec- 
tions one  by  one,  and  by  means  of  fresh  experiments 
overthrew  them.  Thus  Merton  and  Strutt  had,  in  a 
special  apparatus,  failed  to  get  some  of  Collie's  results,  but 

1  Trans.  Chun.  Soc.,  1913,  103,  264.        2  Nature,  1913,  90,  645. 


156     MODERN   CHEMISTRY  AND   ITS  WONDERS 

Collie  in  19141  using  Merton's  own  apparatus  obtained 
very  considerable  quantities  of  helium  and  neon  by  bom- 
barding powdered  uranium  metal  in  an  atmosphere  of 
hydrogen.  Collie  seems  to  have  proved  that  the  nature 
and  size  of  the  electrical  coils  and  tubes  used  in  the 
experiments  have  a  great  influence  on  the  results.  The 
most  recent  experiments  of  Collie2  and  his  co-workers 
seem  to  strengthen  the  evidence  in  favour  of  an  actual 
production  of  certain  elements  by  the  breakdown  of 
stable  elements,  and  here  the  matter  rests. 

At  the  present  time,  therefore,  chemistry  is  in  the 
throes  of  a  great  revolution,  and  the  whole  scientific 
world  awaits  with  suspense  the  upshot  of  these  new  in- 
vestigations. 

Chemists  are  now  told,  by  serious  and  accurate 
workers,  that  the  atomic  weights  of  certain  elements  can 
vary  by  as  much  as  1  per  cent,  according  to  the  parentage 
of  those  elements  ;  he  is  told  that  the  physical  constants 
of  metals  as  now  known  are  worthless,  because  they  are 
in  a  state  of  perpetual  allotropic  change;  finally,  he  is 
confronted  with  the  disintegration  of  the  elements  them- 
selves under  electric  forces.  The  chemist  of  to-day,  then, 
is  in  a  state  of  bewilderment  and  uncertainty :  all  certain 
ground  seems  slipping  away  from  underneath  his  feet,  and 
he  now  awaits  with  breathless  impatience  the  great 
generalisation  which  shall  link  up  the  new  with  the  old 
chemistry,  and  out  of  the  ruins  of  the  latter  build  up  a 
new  philosophy. 

1  J.  N.  Collie,  Proc.  Roy.  Soc.t  1914  [A],  90,  554. 

2  Collie,  Patterson  and  Masson,  Proc.  Roy.  Soc.,  1914  [A],  91,  30. 


CHAPTER    VIII 

APPLICATIONS    OF    ELECTRICITY    TO    CHEMISTRY 

SOME  twenty-five  years  ago  the  famous  German  chemist, 
Victor  Meyer,  when  addressing  an  assembly  of  his  brother 
chemists,  boldly  prophesied  that  "  There  can  be  no  doubt 
that  new  and  undreamt  of  discoveries  will  manifest  them- 
selves, that  a  new  chemistry  will  disclose  itself,  when  we 
are  furnished  with  vessels  that  will  enable  us  to  work  at 
temperatures  at  which  water  can  no  longer  exist,  and  at 
which  a  mixture  of  oxygen  and  hydrogen  gases  becomes 
an  uninflammable  mixture."  Modern  science  is  rapidly 
realising  the  predictions  of  this  great  chemist.  For 
recently  not  only  have  we,  by  means  of  electricity,  been 
able  to  attain  temperatures  so  intense  as  to  rival  those 
on  the  sun  itself,  but  we  have  also  discovered  means 
for  dealing  with  these  temperatures,  for  confining  and 
utilising  them,  in  a  way  that  was  unheard  of  in  Meyer's 
day.  And  what  has  been  the  result  ?  A  new  fairyland 
of  science  has  come  into  existence,  great  chemical 
industries,  employing  thousands  of  men  and  millions 
of  money,  have  sprung  up  as  if  by  magic ;  and  an 
enormous  number  of  new  and  important  compounds, 
products  of  these  mighty  temperatures,  have  been  brought 
to  light,  the  proper  utilisation  of  which  is  now  being 
worked  out  with  feverish  rapidity.  The  introduction  of 
the  electric  furnace  has,  indeed,  not  only  revolutionised 
chemical  industry  in  many  of  its  branches,  but  has  also 
established  several  new  industries  of  its  own. 

157 


158     MODERN   CHEMISTRY  AND  ITS  WONDERS 

We  propose  to  give  a  short,  and  necessarily  incom- 
plete, account  of  these  new  chemical  methods.  We  will 
start  by  describing  the  electric  furnace  itself  as  it  left  the 
hands  of  Moissan. 

This  is  simplicity  itself.  It  merely  consists  of  a  very 
powerful  arc,  produced  between  two  carbon  electrodes, 


FIG.  11. — Moissan's  electric  furnace. 

placed  in  a  cavity  of  minimum  size  at  a  certain  distance 
above  the  substance  to  be  heated.  In  this  way  the  heating 
action  of  the  current  is  separated  from  the  electrolytic 
action.  The  carbon  electrodes  are  placed  between  two 
slabs  of  quicklime,  carefully  cut  and  superposed.  The 
lower  slab  has  a  long  groove  in  which  the  electrodes  rest, 
and  in  the  middle  is  a  small  cavity  which  acts  as  a 
crucible.  On  passing  a  powerful  electric  current  a 


ELECTRICITY    APPLIED    TO    CHEMISTRY      159 

temperature  of  over  3500°  is  produced.  It  is  limited  to 
this,  because  above  this  temperature  the  carbon  electrodes 
simply  boil  away.  It  is  possible  that  in  the  arc  itself  a 
temperature  of  nearly  6000°  C.  may  be  obtained.  By  the 
aid  of  this  simple  arrangement  Moissan  was  able  to 
demonstrate  the  great  utility  of  the  furnace  for  reducing 
many  metals,  like  chromium  and  molybdenum,  which 
are  unmanageable  at  the  highest  temperature  of  an 
ordinary  furnace.  He  also  employed  it  for  making 
calcium  carbide,  carborundum,  and  a  host  of  other 
valuable  products. 

One  of  the  first  industries  to  develop  was  the  manu- 
facture of  calcium  carbide,  CaC2,  used  for  making  acetylene 
gas  and  for  fixing  the  nitrogen  of  the  air  in  the  form  of 
that  valuable  manure  known  as  "  Nitrolime  "  or  calcium 
cyanamide,  which  we  have  discussed  in  our  previous 
book,  Triumphs  and  Wonders  of  Modern  Chemistry. 

Coke  and  lime  reduced  to  pieces  about  the  size  of 
walnuts  are  introduced  into  the  huge  commercial  electrical 
furnaces,  and  a  current  of  some  4000  amperes  at  50  to 
120  volts  is  turned  on.  In  a  very  short  time  a  vast  arc 
flashes  into  existence  and  an  enormous  amount  of  heat  is 
generated.  The  lime  and  the  carbon  then  react  together, 
thus: 

CaO  +  3C  =       CaC2       +          CO 

Lime       Coke      Calcium  carbide       Carbon  monoxide 

These  industrial  carbide  furnaces  are  simply  arc  lamps 
on  a  gigantic  scale.  However,  instead  of  carbons  having 
the  size  and  shape  of  pencils,  those  used  at  the  top  of  the 
furnace  look  more  like  one  of  the  huge  blocks  built  into 
the  foundations  of  a  breakwater.  The  smallest  carbide 
furnaces  used  at  Odda  in  Norway  each  consume  electrical 
energy  equivalent  to  1850  horse-power.  The  liquid  white- 
hot  carbide — at  the  enormous  temperature  of  3500°  C. 


160     MODERN  CHEMISTRY  AND   ITS  WONDERS 

(compared  to  which  molten  iron  as  it  pours  from  great 
blast  furnaces  is  cold) — is  tapped  out  of  the  bottom  of  the 
furnaces  into  heavy  cast-iron  moulds,  and,  after  cooling, 
is  crushed,  sorted  into  sizes,  and  distributed  throughout 
the  world. 

From  Odda  in  Norway  at  first  only  32,000  tons  of 
carbide  were  produced.  At  the  present  time  some  80,000 
tons  are  made  at  one  factory,  and  extensions  are  planned 
which  will  bring  the  output  up  to  the  enormous  total  of 
128,000  tons  annually. 

In  addition  to  this,  carbide  is  being  poured  out  of  the 
high  temperature  factories  in  America,  Italy,  Switzerland 
and  other  centres  of  the  industry.  So  that  the  carbide 
industry  is  now  one  of  the  great  world  industries,  called 
into  existence  almost  overnight  by  the  magic  wand  of 
the  chemist. 

The  next  step  is  the  conversion  of  the  carbide  into 
cyanamide,  by  heating  it  to  about  800°  C.  in  special  retorts 
and  forcing  in  atmospheric  nitrogen.  The  following 
change  takes  place : 

CaC2      +       N2     =       CaN2C       +       C 

Calcium  carbide       Nitrogen      Calcium  cyanamide        Graphite 

It  will  be  seen  that  some  of  the  carbon  of  the  carbide 
separates  out  as  graphite.  The  nitrogen  is  obtained  by 
liquefying  the  air  by  the  Linde  or  Claude  process  and 
fractionally  distilling  it.  By  this  means  the  nitrogen  is 
separated  from  the  oxygen.  At  Odda  the  Linde  plant 
of  the  Nitrogen  Fertilizers  Ltd.,  is  the  largest  in  the  world. 
About  100  tons  of  air  are  liquefied  each  day  and  the 
contained  nitrogen  extracted,  and  forced  under  pressure 
into  the  furnaces  containing  the  calcium  carbide,  which 
is  crushed  to  a  very  fine  powder.  The  initial  heating  is 
started  by  carbon  resistances  running  through  the  centres 
of  the  furnaces  ;  combination  soon  takes  place,  and  once 


ELECTRICITY    APPLIED    TO    CHEMISTRY     161 

the  action  has  started  it  continues  of  itself,  the  nitrogen 
being  sucked  in  and  combined  with  the  carbide  with  the 
evolution  of  great  heat.  The  resulting  calcium  cyanamide, 
or  Nitrolime,  containing  about  20  per  cent,  of  nitrogen, 
appears  as  a  grey-black  stone-like  mass.  It  is  cooled, 
crushed,  ground  to  a  fine  power,  treated  with  a  little 
water  (to  decompose  any  unchanged  carbide)  and  after 
drying  and  storing  is  sent  into  commerce  as  an  important 
nitrogenous  manure.  Indeed  it  is  equal  in  all  respects 
to  Chile  saltpetre.  Owing  to  the  world's  growing  popu- 
lation and  the  growing  exhaustion  of  the  soil,  the  demand 
for  nitrogenous  manure  by  farmers  vastly  exceeds  the 
supply.  As  fast  as  the  manure  can  be  turned  out  it  is 
bought  up  and  applied  to  the  soil  in  order  to  increase 
the  yield  of  wheat  and  grain.  Without  this  nitrogenous 
manure  the  world's  output  of  grain  could  not  meet  the 
growing  demand,  and  dread  famine  and  want  would  soon 
stalk  throughout  the  world. 

As  a  consequence  enormous  developments  of  the 
cyanamide  industry  are  taking  place  throughout  the  world. 
Canada  and  the  United  States  (at  Niagara)  are  erecting 
huge  factories.  Norway  and  Sweden  are  being  trans- 
formed even  as  I  write.  Scientists  are  unanimous  that 
the  world  has  been  for  many  years  advancing  towards  a 
state  of  soil  starvation.  Crops  are  not  keeping  pace 
with  the  increase  in  population — not  because  of  decrease 
in  agricultural  activity  but  because  the  land  has  been 
drained  of  its  combined  nitrogen  through  years  of 
strenuous  cultivation.  Each  harvest  takes  away  more 
nitrogenous  matter  than  is  replaced  by  grazing  and  other 
methods  known  to  farmers  ;  and  to  make  things  grow 
again,  nitrogenous  matter  must  once  more  be  applied  to 
the  soil  to  give  back  that  which  has  been  abstracted. 

Scientists  have  asserted  that  about  12,000,000  tons 
of  nitrate  will  be  necessary  to  produce  the  corn  required 

L 


162      MODERN  CHEMISTRY  AND  ITS  WONDERS 

between  the  present  time  and  1935.  Hence  the  general 
recourse  of  farmers  to  artificial  nitrogenous  manures. 
If  the  earth  is  to  meet  the  ever-increasing  demand  for 
corn  and  food  it  must  have  more  nitrogen. 

To  supply  this  want  the  vast  industry  of  calcium 
cyanamide  has  sprung  up  in  all  lands  possessed  of  cheap 
water-power — the  "  white-coal "  of  science  and  romance 
which  supplies  electrical  energy  for  making  these  high 
temperature  products.  Nowhere  else  can  these  electrical 
industries  take  their  rise  and  being.  Hence  the  awakening 
into  life  of  the  frozen  North,  of  Iceland,  Norway  and  Sweden. 
Sportsmen  and  tourists  would  never  dream  that  the  wild 
grandeur  of  Norwegian  scenery  conceals  in  its  rushing 
waterfalls  and  down-pouring  torrents  unlimited  possi- 
bilities for  supplying  powers  for  these  new  industries. 
Yet  so  it  is,  and  even  at  the  present  time,  in  the  heart 
of  the  mountain-flanked  fiords  of  Scandinavia,  enormous 
operations  and  changes  are  taking  place. 

Thus,  at  Tyssefaldene,  on  the  Sor  Fiord — a  branch 
of  the  celebrated  Hardanger  Fiord — an  immense  reservoir 
has  been  constructed,  with  a  capacity  of  400,000,000 
gallons,  and  the  water  is  conducted  through  a  tunnel 
pierced  through  the  very  heart  of  the  mountains  to  the 
power-station  at  Tysse,  on  the  shores  of  the  Fiord. 
About  83,000  horse-power  are  now  available.  Consequently 
in  the  Tysse  district  electrical  power  is  cheap,  and  so  two 
great  concerns — the  Alby  United  Carbide  Factories,  Ltd., 
and  the  Nitrogen  Products  and  Carbide  Company,  Ltd.,  at 
Odda  have  come  into  existence  for  the  manufacture  of 
these  products.  So  that  although  the  production  of 
calcium  cyanamide  (nitrolime)  was  only  started  in  1907, 
yet  in  1913  about  223,500  tons  were  produced  in  the 
whole  world,  the  two  above-mentioned  factories  con- 
tributing about  88,000  tons. 

But  developments  are  still  proceeding  in  Scandinavia 


PLATE  8. — Rhodesia's  Gem  :  the  Victoria  Falls. 


3,  E.N.A. 

PLATE  9.— Niagara  Falls. 

FUTURE  CENTRES  OF  CHEMICAL  INDUSTRY. 

Since  electricity  can  be  directly  used  for  generating  intense 
heat  in  furnaces  in  which  steel,  aluminium,  glass,  phosphorus, 
carborundum  and  calcium  carbide  maybe  manufactured,  there 
can  be  no  doubt  that  all  the  great  waterfalls  of  the  world, 
where  now  millions  of  horse-power  run  to  waste,  will  ultimately 
become  great  centres  of  industry  and  manufacture. 


ELECTRICITY    APPLIED   TO    CHEMISTRY     163 

so  as  to  increase  the  output  by  utilising  the  energy  derived 
from  three  other  water-powers  in  Norway  (Aura,  Toke, 
and  Blekestad-Bratland),  whereby  100,000  horse-power 
are  now  being  harnessed  for  the  production  of  another 
200,000  tons  of  cyanamide.  The  Detti-Foss  water-power 
in  Iceland  is  capable  of  supplying  at  least  400,000  horse- 
power more,  so  that  within  a  few  years  there  is  little 
doubt  that  from  Norway,  Sweden  and  Iceland  alone  some 
2,000,000  tons  of  calcium  cyanamide  will  be  poured  into 
the  world's  market  to  supply  our  exhausted  soil  with 
nitrogen — an  output  of  fixed  nitrogen  as  much  as  that 
present  in  the  whole  modern  production  of  Chile  salt- 
petre. 

For  ages  snow  and  ice  have  been  piled  up  in  the 
frozen  North,  which,  melting  in  the  warmth  of  the  sun, 
give  rise  to  rushing  torrent  and  waterfall.  Now  at  last 
these  rugged  and  almost  desert  regions  will  awake  to 
fresh  life  after  the  sleep  of  ages.  At  present  it  is  true 
that  less  than  1,000,000  horse-power  derived  from 
Norway's  waterfalls  has  been  harnessed  for  generating 
electrical  power. 

But  over  200,000,000  horse-power  are  there  available, 
and  just  as  in  the  past  busy  manufacturing  cities  sprang 
up  around  coal-producing  districts,  so  in  the  immediate 
future  great  cities  will  come  into  existence  in  districts 
rich  in  water-power. 

Many  of  us  now  living  will  see  before  we  die  waste 
and  desolate  lands  like  Iceland  converted  into  busy  hives 
of  industry.  Such  is  the  magic  power  of  the  chemist. 
By  the  labours  of  men,  poor,1  unknown  and  usually 
despised,  the  surface  of  the  world  is  transformed,  and 
revolutions  wrought  greater  than  any  brought  by  victorious 
armies  and  the  might  of  kings.  As  Liebig  the  great 
chemist  said  some  fifty  years  ago  : — "  Both  the  rise  and 

1  See  p.  4. 


164     MODERN  CHEMISTRY  AND   ITS  WONDERS 

decline  of  nations  are  governed  by  the  same  law  of 
nature.  The  deprivation  of  the  soil  of  its  conditions  of 
fruitfulness  brings  about  their  decline,  while  the  mainte- 
nance of  such  conditions  leads  to  their  permanence, 
prosperity  and  power.  The  nation  is  not  fed  by  peace 
nor  destroyed  by  war — these  conditions  exert  only  a 
temporary  influence  on  it.  It  is  the  soil  on  which  man 
builds  his  home  which  is  instrumental  in  holding  human 
society  together,  and  in  causing  nations  and  empires  to 
disappear  or  to  become  powerful.  The  absolute  fruitful- 
ness  of  the  ground  is  independent  of  mankind,  but  he 
possesses  the  power  of  diminishing  or  prolonging  such 
fruitfulness." 

Since  it  is  the  chemist,  working  obscurely  in  his  labora- 
tory, that  has  brought  about  these  industrial  revolutions 
and  has  restored  prosperity  to  the  soil  by  his  new  processes 
and  new  substances,  I  think  that  the  reader  will  agree  with 
my  thesis  put  forward  earlier  in  this  book,  that  the  nation 
which  excels  in  chemistry  will  ultimately  attain  world- wide 
power.  The  balance  of  the  chemist  is  mightier  than  the 
sword  of  the  soldier  in  altering  the  destinies  of  the 
human  race. 

Yet  again  there  is  the  new  industry  of  fixation  of  atmos- 
pheric nitrogen  which  is  brought  about  by  driving  air 
through  electrical  furnaces  of  special  construction.  The 
oxygen  and  nitrogen  of  the  air  unite  to  form  oxides  of 
nitrogen  which  when  led  into  water  yield  nitrous  and 
nitric  acids  ;  these  are  then  fixed  by  leading  over  lime- 
stone and  so  are  converted  into  calcium  nitrate  and  nitrite, 
which  in  turn  is  used  as  a  manure.  This  industry  is  now 
rapidly  developing  into  an  enormous  one,  but  as  we  have 
already  given  a  full  account  of  the  methods  employed 
in  the  previous  volume,  Triumphs  and  Wonders  of  Modern 
Chemistry,  I  must  here  refer  the  reader  to  my  former 
book  for  further  details. 


ELECTRICITY    APPLIED    TO    CHEMISTRY      165 

Then  there  is  the  manufacture  of  that  splendid  abrasive, 
carborundum  (silicon  carbide,  SiC),  which  is  now  manu- 
factured on  a  very  large  scale  by  heating  together  sand 
and  coke  in  the  electric  furnace : 

SiO2+  3C  =       SiC       +         2CO 

Sand       Coke      Carborundum      Carbon  monoxide 

The  furnace  is  shown  in  Plate  11,  which  gives  a 
photograph  of  Acheson's  furnace-room.  The  furnace 
consists  of  a  rough  brick  structure,  which  is  pulled 
down  after  each  operation,  and  then  set  up  again  with 
a  fresh  charge.  The  electrodes  are  massive  carbon 
rods  set  longitudinally,  and  the  charge  is  placed  between. 
By  the  same  furnace,  by  modifying  the  proportion  of 
sand,  graphite  is  also  manufactured  for  blacklead  pencils, 
which  is  actually  better  than  the  graphite  dug  out  of 
the  earth.  Siloxicon,  Si2C2O,  is  another  product  manu- 
factured in  a  similar  way  in  the  furnace  by  heating 
sand  with  twice  its  weight  of  coal.  It  appears  to  be  a 
product  of  great  industrial  importance,  because  it  is  quite 
indifferent  towards  high  temperatures,  even  molten  iron 
and  basic  slags  having  no  action  upon  it.  It  is  therefore 
used  for  lining  furnaces. 

As  we  have  already  seen,  nowadays  phosphorus  is  dis- 
tilled out  of  mineral  phosphates  in  the  electric  furnace, 
and  turned  into  matches. 

Innumerable  carbides,  borides,  and  silicides  have  also 
been  formed  recently,  some  already  of  great  commercial 
importance,  others  merely  waiting  to  have  their  useful 
properties  discovered. 

The  organic  compound,  carbon  disulphide,  CS2,  so 
useful  as  a  solvent  and  extractive,  is  now  made  extremely 
cheaply  by  a  continuous  process  in  which  charcoal  and 
sulphur  are  fed  into  the  top  of  a  stack,  at  the  bottom  of 


166     MODERN  CHEMISTRY  AND   ITS  WONDERS 

which  there  is  an  electric  furnace  which  causes  them  to 
combine,  thus : 

C  .+    2S    =          CS2 

Carbon      Sulphur      Carbon  disulphide 

Again,  quartz  tubing  is  now  manufactured  cheaply  in 
the  electric  furnace.  The  process  consists  in  spreading 
sand  (silica)  over  a  carbon  resistance  rod,  and  subsequently 
heating  the  rod  electrically  to  the  melting  point  of  sand, 
when  the  latter  fuses  round  as  a  compact  mass. 

These  tubes  are  of  great  value  to  the  chemist,  as  they 
are  capable  of  standing  enormous  and  sudden  variations 
of  temperature,  besides  being  quite  indifferent  towards  the 
most  corrosive  liquids  (except  hydrofluoric  acid). 

Among  the  most  important  uses  of  the  electric  current 
is  its  employment  for  manufacturing  aluminium  from  clay, 
which  is  now  carried  out  on  a  very  large  scale,  the 
aluminium  being  used  for  making  utensils  and  various 
ornamental  articles.  Even  steel  is  now  made  by  means 
of  the  electric  furnace.  Within  the  last  few  years  many 
thousand  tons  of  the  very  best  steel  have  been  produced 
by  its  means.1 

One  of  the  most  famous  of  these  steel-refining  electric 
furnaces  is  the  H£roult. 

The  electric  current  is  carried  by  two  massive  solid 
carbon  electrodes,  as  thick  as  a  man's  body.  These  are 
about  six  feet  long  and  over  one  foot  in  diameter.  The 
charge,  consisting  of  steel  scrap,  pig  iron,  iron  ore,  and 
lime,  in  suitable  proportions,  is  placed  on  the  hearth  of 
the  furnace  and  raised  to  the  melting  point  by  the 
enormous  alternating  current  of  4000  amperes  at  120 
volts.  The  lime  and  silicates  of  the  ore  fuse  and  form  a 
slag  which  spreads  over  the  surface  of  the  molten  steel, 

1  The  reader  will  find  an  interesting  account  of  the  application  of  the  electric 
furnace  to  steel  making  and  refining  in  Gassier1  s  Magazine,  July  1909,  vol.  36, 
p.  237,  by  Mr.  Kershaw. 


From  Cassier's  Magazine 
PLATE  10. — How  Water-power  is  harnessed  to  produce  Electricity. 

Power  House  of  the  Shawinigan  Water  &  Power  Co.,  Canada,  situated  on  the  St. 
Maurice  River  Falls.  Water  is  conveyed  by  huge  pipes  to  powerful  turbines  situated  in 
the  power-house.  The  turbines  work  dynamos  and  thus  generate  electricity.  100,000 
horse-power  are  capable  of  being  generated  here. 


From  Cassier's  Magazine. 

PLATE  11. — Electric  Furnaces  for  Carborundum  and  Graphite  of  Acheson 
Graphite  Co.,  Niagara  Falls. 

The  furnaces  are  built  of  loose  bricks,  which  are  removed  at  the  end  of  every  operation 
in  order  to  take  out  the  charge. 


ELECTRICITY    APPLIED    TO    CHEMISTRY     167 

thus  protecting  it  from  oxidation.  The  electrodes  are 
now  lowered  until  they  just  dip  below  the  surface  of  the 
molten  slag,  and  in  order  to  oxidise  those  impurities  of 
the  metal  which  it  is  necessary  to  remove,  an  air  blast 
enters  and  oxidises  the  sulphur  and  phosphorus,  which 
are  carried  up  into  the  slag  on  the  surface.  The  furnace 
is  now  tilted  in  order  to  pour  off  this  slag,  and  the  treat- 
ment is  continued  two  or  three  more  times  with  fresh 
quantities  of  lime,  &c.,  until  a  comparatively  pure  metal 
is  left  on  the  hearth  of  the  furnace.  When  this  point  is 
reached  a  calculated  amount  of  an  alloy  high  in  carbon 
(carburite)  is  added  to  the  molten  mass,  and  the  charge 
then  run  out.  The  H£roult  crucible  furnaces  produce, 
as  a  rule,  three  tons  of  the  very  best  steel  at  a  charge. 
A  visit  to  a  work  in  which  these  furnaces  are  employed 
is  indeed  well  worth  making — nothing  else  can  give  an 
idea  of  the  fierce  heat  prevailing  within  the  furnace. 
Many  other  electrical  furnaces,  of  different  make,  are  used 
for  the  same  purpose. 

Another  valuable  development  of  the  electric  furnace 
is  its  employment  for  extracting  rare  and  refractory 
metals,  which  formerly  were  almost  unknown.  Among 
these  metals  are  chromium,  molybdenum,  tungsten, 
titanium,  and  many  others.  On  adding  traces  of  these 
metals  to  steel  its  qualities  and  hardness  are  greatly  im- 
proved. The  La  Neo-metallurgie,  of  Paris,  now  manu- 
factures over  thirty  valuable  metals  and  alloys,  whose 
very  names  were  hardly  known  a  few  years  ago.  The 
Societe  d'Electrochimie  is  another  Parisian  company 
which  manufactures  ferro-silicium  on  a  large  scale.  This 
body,  a  compound  of  iron  and  silicon,  is  especially 
valuable  for  adding  in  small  quantities  to  steel,  the  silicon 
combining  with  impurities  in  the  metal,  and  thus  purifying 
it  in  a  wonderfully  effective  manner.  The  manufacture 
of  metallic  sodium,  calcium,  and  numerous  other  inorganic 


i68     MODERN   CHEMISTRY  AND  ITS  WONDERS 

and  organic  products  of  the  greatest  value  in  commerce, 
by  means  of  the  electric  current,  cannot  here  be  more 
than  mentioned. 

Lastly,  but  not  least,  we  have  a  great  industry  which 
has  arisen  out  of  the  process  of  electrolysing  solutions  of 
brine,  whereby  there  are  produced  caustic  soda,  chlorine, 
chlorates,  bleaching  solutions,  and  various  other  valuable 
products — all  manufactured  by  electricity,  without  the 
hardship  and  distress  inseparable  from  the  use  of  blazing 
furnaces  as  used  in  the  Leblanc  process.  At  the  present 
time  more  than  half  the  copper  in  the  world  is  separated 
from  impurities  by  electro-deposition,  cool  tanks  replac- 
ing the  old-time  smelting  furnaces.  The  process  of 
electro-deposition,  in  fact,  steadily  encroaches  upon  the 
furnace  fires  of  the  foundry,  plates  for  the  printer,  statues 
for  the  sculptor,  and  a  thousand  other  useful  objects 
being  now  produced  by  these  new  processes. 

We  must  stop  here.  Enough  has  been  said,  I  think,  to 
convince  the  reader  that  the  employment  of  electricity  on  a 
large  scale  has,  within  the  last  few  years,  created  a  new 
chemistry  and  a  new  series  of  industries  which  will  go 
far  towards  turning  the  world's  desolate  regions  into 
centres  of  wealth  and  luxury,  thus  partially  realising 
the  dreams  of  the  socialist.  But  one  thing  is  certain. 
Wherever  there  exist  great  quantities  of  running  water, 
wherever  water  power  is  cheap,  there,  no  matter  whether 
it  be  in  the  icy  North,  or  in  sunny  tropical  lands,  will 
arise  in  time  mighty  cities,  centres  of  civilisation  and 
power,  whose  high-temperature  factories  will  distribute 
their  wares  over  the  face  of  the  whole  earth,  to  the 
great  benefit  of  humanity.  For  running  water  can  be 
applied  for  working  turbines,  which  in  their  turn  work 
dynamos,  and  thus  generate  electricity. 

Even  now  the  brow  of  Niagara  Falls  is  encircled  with 
a  diadem  of  high-temperature  factories,  and  great  towns  are 


ELECTRICITY    APPLIED    TO    CHEMISTRY      169 

springing  up  around  them  in  every  direction.  In  Norway  the 
running  waters  are  being  harnessed  to  generate  the  electric 
current  for  the  manufacture  of  artificial  nitrates,  while  in 
the  near  future  we  may  expect  to  see  great  cities  springing 
up  on  the  Zambesi  in  Central  Africa,  and  on  those  vast 
mysterious  Falls  in  the  centre  of  South  America,  which 
have  as  yet  been  seen  by  the  eyes  of  very  few  white  men. 

Within  recent  years  the  electric  current  has  been  put 
to  another  use  which  we  must  here  touch  upon.  The 
whole  tendency  of  modern  civilisation  is  towards  rapidity, 
whether  it  be  in  work,  thought,  or  play.  And  nowhere, 
perhaps,  is  this  general  tendency  more  evident  than  in 
modern  analytical  methods.  In  many  commercial  pro- 
cesses it  is  absolutely  essential  that  the  different  products 
should  be  rapidly  and  accurately  analysed,  and  so  it 
comes  about  that  old  laborious  methods  are  being  gradu- 
ally replaced  by  modern  methods  which  combine  high 
speed  with  accuracy. 

For  example,  we  might  mention  in  this  connection 
the  new  simple  and  rapid  methods  for  estimating  arsenic, 
copper  and  iron  introduced  by  Prof.  G.  D.  Lander,  of  the 
Royal  Veterinary  College.1 

Perhaps  the  most  startling  of  the  later  innovations 
is  the  application  of  electricity  to  chemical  analysis.  The 
new  electrical  methods,  in  fact,  threaten  to  displace  the  old 
laborious  gravimetric  methods  for  estimating  certain  metals, 
for  by  their  means  we  can  carry  out  analyses  in  a  few 
minutes,  which  by  older  methods  would  have  taken  many 
hours  or  even  days  to  complete. 

The  old  gravimetric  processes  for  estimating  metals 
consist  in  precipitating  them  from  their  solution  as  in- 
soluble salts  by  adding  a  suitable  reagent,  transferring  the 
mass  to  a  filter  paper,  washing  until  free  from  all  impurity, 
drying,  heating,  and  weighing — operations  which  often 

1  See  Lander  £  Geake,  the  Analyst ',  March,  1914. 


170     MODERN  CHEMISTRY  AND  ITS  WONDERS 

take  many  hours  to  perform.     If  two  or  three  different 
metals  are  present  in  the  solution  the  operation  must  be 


FIG.  12. — Section  through  Dr.  Sand's  Apparatus  for  Rapid  Electro- Analysis. 

repeated  separately  for  each  different  metal ;  so  that  it 
is  often  extremely  difficult,  as  well  as  very  laborious,  to 
separate  out  several  such  metals  from  a  solution,  the 
whole  series  of  operations  often  taking  days  to  complete. 
Recently,  however,  rapid  electrical  methods  have  been 


ELECTRICITY    APPLIED    TO    CHEMISTRY      171 

introduced  which,  to  a  great  extent,  do  away  with  these 
laborious  processes.  In  these  the  metal  to  be  determined 
is  deposited  on  a  platinum  electrode  by  the  electric  current, 
and  is  then  weighed.  Wolcott  Gibbs  in  America,  in 
1864,  and  Luckow  in  Germany  were  the  first  to  grasp 
the  possibilities  of  electro-analysis,  and  showed  how  the 
operation  was  to  be  carried  out.  Since  that  time  a  large 
number  of  distinguished  chemists  have  been  busy  ela- 
borating these  methods  and  elucidating  their  theory. 
Among  these  may  be  mentioned  Classen,  Vortmann, 
Winkler,  Forster,  Nernst,  Leblanc,  Freudenburg,  and 
Hollard.  In  recent  years,  however,  these  electrical 
methods  have  been  very  greatly  extended  and  improved, 
especially  as  regards  the  time  required  for  an  analysis, 
by  Gooch,  Medway,  Smith,  Exner,  and  others  in  America. 
In  England  Dr.  Sand,  of  University  College,  Nottingham, 
has  invented  apparatus  which  brings  the  method  to  a 
wonderful  state  of  perfection.  Plate  12  is  a  photograph 
of  the  apparatus  used  by  Dr.  Sand  for  the  successive 
estimation  of  a  large  number  of  metals  when  present 
simultaneously  in  the  solution.  Each  metal  separates 
out  at  a  different  electrical  tension,  so  that  by  measuring 
the  difference  of  potential  between  the  liquid  itself  and 
the  electrode  on  which  the  metal  is  being  deposited  by 
an  auxiliary  electrode — an  improvement  introduced  into 
electro-analysis  by  Dr.  Sand  in  1907 — the  current  can  be 
regulated  in  such  a  manner  that  only  one  metal  separates 
out  at  a  time.  When  it  has  been  completely  deposited 
the  current  usually  almost  ceases  to  pass  through  the 
liquid,  so  that  the  analyst  knows  when  to  stop.  Extreme 
rapidity  of  deposition  is  secured  by  stirring  the  liquid  to 
be  analysed  vigorously  by  means  of  special  motor-driven 
electrodes  (see  figs.  12,  13),  and  at  the  same  time  passing 
a  powerful  current  through  the  solution.  Unless  the 
liquid  is  rapidly  stirred,  the  electricity  at  once  exhausts  it 


172      MODERN   CHEMISTRY  AND  ITS  WONDERS 

of  metal  at  the  cathode,  and  then  decomposes  the  water 
around  it,  generating  hydrogen,  and  thus  destroying  all 
possibility  of  accurate  analysis.  Stirring  replenishes  the 
liquid  at  the  electrode  as  fast  as  it  is  exhausted,  and  thus 


FIG.  13. — Dr.  Sand's  Electrodes  for  Electro-Analysis. 

secures  that  the  metal  is  deposited  at  a  constant  potential. 
When  the  metal  is  completely  deposited  from  the  solu- 
tion— which  takes  five  to  ten  minutes  as  a  rule — the 
cathode  is  removed,  rinsed  with  water,  alcohol,  and  ether, 
and  dried  over  a  Bunsen  flame — operations  carried  out 
in  barely  a  minute.  It  is  then  weighed,  and  the  metal  pre- 
cipitated on  it  is  thus  determined.  A  few  examples  taken 


ELECTRICITY    APPLIED    TO    CHEMISTRY      173 

from  Dr.  Sand's  most  recent  papers  x  will  illustrate  the 
surprising  efficiency  and  rapidity  of  these  new  methods. 
Perhaps  one  of  the  most  difficult  of  electro-analytical 
operations  was  the  separation  of  metallic  bismuth  in  a 
form  suitable  for  analysis.  Dr.  Sand  now  achieves  this 
with  ease  and  certainty  in  only  a  few  minutes.  Thus  a 
solution  containing  0*2184  gram  of  bismuth  gave  0*2187 
gram  in  nine  minutes.  The  determination  of  the  amount 
of  copper  and  lead  in  a  solution  would  take  several  hours 
gravimetrically.  Electrically  a  few  minutes  suffice.  Thus 
in  one  experiment  Dr.  Sand  passed  a  current  of  two 
amperes  for  five  minutes  through  the  hot  solution.  The 
lead  was  in  this  short  time  all  deposited  on  the  anode  as 
lead  peroxide,  PbO2.  The  current  was  then  increased  to 
10  amperes,  and  the  copper  was  deposited  on  the  cathode 
as  metal.  On  weighing  the  cathode  and  anode  the  re- 
spective amounts  of  copper  and  lead  were  found  to  be 
0*2476  gram  and  0*1383  gram  respectively.  Theory  re- 
quired 0*2474  gram  copper  and  01383  gram  of  lead. 
These  results  speak  for  themselves.  But  they  are  only  two 
of  many  others  which  could  be  quoted  did  space  permit. 

It  may  be  added  that  the  process  is  not  confined  to 
separating  rapidly  two  metals  alone,  but  three,  four,  five, 
six,  and  even  seven  metals  can  with  equal  ease  and  rapidity 
be  separated.  Thus  in  one  case  Dr.  Sand  analysed  a 
solution  containing  silver,  mercury,  copper,  bismuth,  lead, 
cadmium,  and  zinc — an  operation  which  would  have  been 
extraordinarily  difficult  to  carry  out  in  many  days  by  the 
ordinary  gravimetric  processes.  But  enough  has  been 
said  to  show  the  importance  of  these  new  methods.  They 
prolong  the  effective  life  of  the  analyst  much  beyond  its 
former  extent,  and  may  possibly  in  the  immediate  future 
become  of  great  commercial  importance  as  well. 

1  "The  Rapid  Electro-analytical  Deposition  and  Separation  of  Metals,"  by 
Dr.  H.  J.  S.  Sand,  Joiirnal  of 'the  Chemical  Society  (1907),  vol.  91,  p.  373. 


174     MODERN  CHEMISTRY  AND  ITS  WONDERS 

Still  one  more  application  of  electricity  I  must  touch 
upon,  and  that  is  its  use  in  chemical  research.  Electricity 
may  be  said  to  be  the  great  revealer  of  the  inner  mysteries 
of  matter.  It  has  lighted  up  the  lamp  of  research,  enab- 
ling such  workers  as  Crookes,  Thomson,  and  Rutherford 
to  penetrate  into  the  dark  interiors  of  the  very  atoms  of 
matter.  By  means  of  the  electric  current  the  atom  has 
been  shattered,  the  mysteries  of  radium,  thorium,  and 
uranium  investigated,  and  so  the  great  fact  of  the  dis- 
integration of  matter  revealed.  If  fire  gave  the  chemist 
command  of  molecules,  electricity  has  enabled  him  to 
resolve  the  atom  into  even  more  nearly  ultimate  particles. 

Not  only  does  the  atom  appear  divisible,  under  the 
electric  current,  but  it  is  held  by  some  that  the  elements 
are  themselves  transmutable  by  its  aid,  and  so  the  ancient 
doctrines  of  alchemy  have  been  revived  in  modern  garb. 
The  electric  rays  have  been  utilised  for  demonstrating 
the  existence  of  individual  atoms  ;  by  their  aid  the  arrange- 
ment of  atoms  in  crystals  have  actually  been  photographed 
— so  it  is  claimed  by  sober  investigators.  And  thus  the 
electric  ray  has  revealed  for  science  a  new  heaven  and 
a  new  earth,  utterly  transcending  the  motions  and  the 
phases  of  matter  which  the  chemists  of  a  few  decades 
ago  regarded  as  ultimate. 


CHAPTER  IX 

THE  ROMANCE  OF  THE  HYDROCARBONS 

FEW  regions  of  the  world  are  more  remarkable  than  the 
lands  surrounding  the  Caspian  Sea.  Once  they  were 
covered  by  the  dark  waters  of  a  great  inland  sea,  which 
stretched  north  and  joined  the  Arctic  Ocean.  In  very 
ancient  times,  however,  a  process  of  slow  drying  up 
commenced.  The  icy  waters  steadily  receded  until  after 
many  ages  they  are  now  confined  to  the  narrow  limits 
of  the  present  Caspian  Sea.  As  the  waters  retreated 
they  left  behind  them  vast  stretches  of  waste  and  barren 
land,  which  to-day  extend  as  far  as  the  eye  can  reach. 
No  natural  meadows  gladden  the  view  of  a  stranger  visit- 
ing these  districts.  Instead  there  stretches  before  him 
an  immense  desert  of  white  sand  and  reddish  clay,  with 
here  and  there  some  scanty  shrubs  with  dark,  sombre 
leaves.  At  frequent  intervals  occur  ravines  worn  in  the 
soil  by  the  torrents  of  a  thousand  storms,  and  marshes 
filled  with  reeds  and  thick  slimy  waters.  Truly  a  waste, 
forbidding  region !  For  centuries  the  land  has  been 
called  the  "  Region  of  Everlasting  Fire."  And  with  some 
show  of  reason,  too.  For  anyone  wandering  after  sunset 
in  the  interminable  plain  can  see  rising  on  all  sides  from 
rents  and  crevices,  moving  flames,  bright  fantastic  tongues 
of  fire,  which  untarnished  by  smoke  wave  their  bright 
summits  to  and  fro  in  the  darkness,  as  if  beckoning  him 
on  to  destruction : 

"  A  savage  place !  As  holy  and  enchanted 
As  e'er  beneath  a  waning  moon  was  haunted 
By  woman  wailing  for  her  demon-lover  !  " 
175 


176     MODERN   CHEMISTRY  AND    ITS  WONDERS 

These  flames  are  not  the  disembodied  souls  of  dead  men 
or  demons,  as  was  once  thought  by  the  natives,  but  rather 
are  due  to  torrents  of  a  gas,  very  similar  to  our  coal  gas, 
which,  pouring  out  from  underground  regions,  have  become 
ignited  by  a  process  of  spontaneous  combustion.  The 
earth  in  these  districts  has  been  evolving  these  gases  for 
ages.  Indeed,  if  the  reader  should  visit  Surakhani,  on  the 
shores  of  the  Caspian,  he  will  be  able  to  see  a  temple 
built  by  fire-worshippers,  from  whose  towers  streams  aloft 
a  column  of  burning  gas.  If  the  priests  are  to  be  be- 
lieved, this  column  has  burnt  without  intermission  since 
400  years  before  Christ.  Although  this  statement  is  pro- 
bably incorrect,  yet  there  can  be  little  doubt  that  some 
of  these  remains  are  of  immense  antiquity,  and  probably 
date  from  the  time  of  Zoroaster,  600  years  B.C.  The 
present  temple,  of  Indian  origin,  is  a  fortified  square 
with  a  high  towered  gate.  In  the  centre  of  the  court 
stands  a  square  building  supported  by  four  columns, 
and  enclosing  a  basin-like  excavation  whence  gas  streams 
upwards  and  is  conducted  into  the  tower  and  its  four 
chimneys.  The  gas  burns  at  a  low  pressure,  and  can 
be  readily  blown  out  and  relighted.  The  flame  is  rather 
bluish  and  does  not  give  much  light ;  at  night  it  presents 
a  most  weird  appearance.  Ancient  stone  beds  and  stalls, 
with  mangers  cut  out  of  the  stone,  for  the  pilgrims  and 
their  beasts,  still  remain  in  the  hollow  walls,  and  various 
small  chapels  and  dungeon-like  rooms  doubtless  appear 
now  as  they  did  centuries  ago  (Plate  13). 

Near  the  temple  a  well  may  be  seen  some  fifty  feet 
deep,  in  which  the  gas  accumulates  in  very  large  quantities. 
It  was  here  that  the  German  traveller  Koch  witnessed  a 
very  strange  sight.  The  priest  and  his  assistants  spread  a 
carpet  over  the  mouth  of  the  well  to  prevent  the  gas 
from  escaping.  After  being  left  on  for  a  few  minutes, 
it  was  quickly  removed,  and  a  bundle  of  brushwood  in 


From  Cassier's  Magazine. 
PLATE  13. — An  ancient  Fire- worshipper's  Temple  near  Balakhani. 


From  Cassier's  Magazine. 
PLATE  14.— A  glimpse  of  the  famous  Russian  Oil  City  of  Baku. 


xo 


ROMANCE  OF  THE  HYDROCARBONS   177 

:ch   a  piece   of  burning   paper    had  been   stuck,  was 

own  down  the  cavity.     This  done,  the  priest  and  his 

jistants  ran  off  as  fast  as  they  could.     Suddenly  a  great 

plosion  took  place  in  the  well  and  an  immense  column 

fire  leaped  forth  and  ascended  to  the  skies. 

Hanway,  who  visited  the  country  in  1754  on  behalf 


FIG.  14. — Explosion  of  gas  in  a  well  at  Surakhani. 

of  the  British  government,  thus  reports  on  the  district : 
"  What  the  Guebers,  or  Fire-worshippers,  call  the  Ever- 
lasting Fire,  is  a  phenomenon  of  a  very  extraordinary 
nature.  This  object  of  devotion  lies  about  ten  English 
miles  north-east  by  east  from  the  city  of  Baku,  on  a  dry 
rocky  land.  There  are  several  ancient  temples  built  with 
stone,  supposed  to  have  all  been  dedicated  to  fire. 
Amongst  others  is  a  little  temple  at  which  Indians  now 

M 


178     MODERN  CHEMISTRY  AND  ITS  WONDERS 

worship.  Here  are  generally  forty  or  fifty  of  these  poor 
devotees,  who  come  on  a  pilgrimage  from  their  own 
country.  A  little  way  from  their  temple  is  a  low  cleft  in 
a  rock,  in  which  there  is  a  horizontal  gap,  two  feet  from 
the  ground,  nearly  six  feet  long,  and  about  three  broad, 
out  of  which  issues  a  constant  flame,  in  colour  and  gentle- 
ness not  unlike  a  lamp  that  burns  with  spirits,  only  more 
pure.  When  the  wind  blows,  it  rises  sometimes  eight 
feet  high,  but  is  much  lower  in  still  weather.  They  do 
not  perceive  that  the  flames  make  any  impression  on  the 
rock.  This  also  the  Indians  worship,  and  say  it  cannot 
be  resisted,  but  if  extinguished  will  rise  in  another  place. 
The  earth  around  the  place,  for  above  two  miles,  has 
this  surprising  property,  that  by  taking  up  two  or  three 
inches  of  the  soil  and  applying  a  live  coal,  the  part  which 
is  so  uncovered  will  immediately  take  fire,  almost  before 
the  coal  touches  the  earth  ;  the  flame  makes  the  earth 
hot,  but  does  not  consume  it,  nor  affect  what  is  near  it 
with  any  degree  of  heat.  .  .  .  Not  long  since  eight 
horses  were  consumed  by  this  fire,  being  under  a  roof 
where  the  surface  of  the  ground  was  turned  up,  and  by 
some  accident  took  flame.  If  a  cane  or  tube  even  of 
paper  be  set  about  two  inches  in  the  ground,  confined 
and  closed  with  earth  below,  and  the  top  of  it  touched 
with  a  live  coal,  and  blown  upon,  immediately  a  flame 
issues  without  hurting  either  the  cane  or  paper,  provided 
the  edges  be  covered  with  clay,  and  this  method  they 
use  for  light  in  their  houses,  which  have  only  the  earth 
for  floor  ;  three  or  four  of  these  lighted  canes  will  boil 
water  in  a  pot,  and  thus  they  dress  their  victuals.  .  .  . 
Lime  is  burnt  to  great  perfection  by  means  of  this 
phenomenon,  the  flame  communicating  itself  to  any  dis- 
tance where  the  ground  is  uncovered  to  receive  it.  The 
stones  must  be  laid  on  one  another  and  in  three  days 
the  lime  is  completed." 


ROMANCE  OF  THE  HYDROCARBONS   179 

A  modern  writer  thus  describes  the  same  region : l 
"  From  this  point  (Eblahk)  the  road  runs  directly  to 
Baku  over  180  miles  of  desert  land.  Except  for  an 
occasional  Tartar  Settlement  or  government  railway 
station,  not  a  house  is  to  be  seen,  and  the  only  signs 
of  life  are  a  stray  horseman  or  an  occasional  camel  train. 
The  level  of  the  track  is  now  above  and  now  below  the 
sea,  the  lowest  point  being  70  feet  below  the  level  of  the 
Black  Sea.  On  the  north  the  mountains  recede  and  are 
replaced  by  a  low  outline  of  hills  absolutely  devoid  of 
verdure,  whereas  on  the  south  the  river,  which  has 
accompanied  the  road  from  the  summit  of  the  mountain, 
gradually  diverges  and  empties  into  the  Caspian  Sea  about 
100  miles  from  Baku.  It  is  supposed  that  this  river  bed 
once  took  the  same  course  as  the  present  railway,  since 
unmistakable  signs  of  former  villages  and  even  farms 
are  constantly  being  unearthed  in  this  arid  region.  .  .  . 
On  approaching  Baku  evidences  of  the  oil  fields  become 
visible  on  all  sides,  and  great  cities  of  black  derricks,  set 
so  close  together  that  they  appear  like  a  dense  forest, 
mark  the  well  defined  area  of  the  productive  field.  As 
the  train  circles  round  a  well-sized  hill  the  city  of  Baku 
bursts  upon  the  vision  with  startling  suddenness,  and  one 
is  soon  in  what  might  well  be  called  one  of  the  most 
interesting  cities  of  modern  times.  It  lies  on  the  sloping 
shore  of  the  very  salty  Caspian  Sea,  and  is  credited  in 
ancient  legends  to  have  once  borne  the  name  which  in 
Tartar  language  means  City  of  Roses.  Nothing,  however, 
could  be  more  inappropriate  at  the  present  time,  when  the 
ruling  impression  is  complete  absence  of  verdure,  due  to 
lack  of  fresh  water  supply.  All  the  water  used  by  this 
city  of  over  75,000  inhabitants  is  now  either  distilled  from 
the  sea-water,  brought  in  tank  cars  from  distant  rivers, 
or  borne  in  casks  on  the  backs  of  horses  or  camels  from 

1  Ernest  Potter  in  Gassier  s  Magazine,  Nov.  1900,  vol.  19,  p.  3. 


i8o     MODERN   CHEMISTRY  AND  ITS  WONDERS 

very  carefully  preserved  wells  in  the  vicinity  and  fed  by  not 
too  frequent  rains.  .  .  .  Evidences  of  wealth  are  not  only 
to  be  seen  in  the  appearance  of  the  city  itself,  but  also 
among  many  of  the  inhabitants.  It  is  not  an  uncommon 
sight  to  see  a  Tartar  or  Persian  who  is  worth  a  fortune, 
but  who  cannot  write  his  own  name,  and  has  no  idea  of 
the  world  outside  Baku." 

Such  gas-wells;  however,  are  not  confined  to  this  one 
region  of  the  world.  They  occur  widely  distributed  in 
almost  every  part  of  the  globe.  In  North  America  they 
are  specially  plentiful.  And  here  the  gas  often  is  impelled 
upwards  with  immense  force.  Indeed  it  has  been  known 
suddenly  to  rush  forth  from  deep  borings  under  a  pressure 
of  1000  Ibs.  to  the  square  inch.  At  an  immense  gas-well 
at  Delameter  in  the  United  States,  enough  gas  was  evolved 
to  supply  the  whole  town  and  the  neighbouring  districts 
with  heat  and  light.  Several  pipes  carried  off  the  gas, 
one  leading  it  direct  to  the  cylinder  of  a  large  engine, 
and  so  great  was  the  pressure  that  the  engine  continuously 
worked  at  great  speed.  When  the  gas  issuing  from  the 
cylinder  was  set  on  fire  it  threw  out  a  mass  of  flames  and 
could  have  been  employed  for  driving  another  engine. 
Another  pipe  supplied  a  flame  capable  of  reducing  ore 
enough  to  supply  half  the  furnaces  of  Pittsburg.  A  third 
pipe,  three  inches  in  diameter,  sent  up  a  column  of  fire 
forty  feet  high.  On  a  calm  night  the  roaring  of  the  flames 
could  be  heard  fifteen  miles  away.  The  gigantic  flame 
shooting  up  into  the  air  presented  the  appearance  of  a 
burning  steeple-  Another  well  at  Fairview  supplied  a 
hundred  engines  for  many  years  with  gas,  and,  I  believe, 
is  still  supplying  them.  Many  hundreds  of  such  gas- wells 
are  known,  far  too  many  for  us  to  attempt  to  enumerate 
them  here. 

Wherever  we  find  gas  coming  up  to  the  surface  from 
subterranean  sources  in  such  great  quantities  we  can  be 


Prom  Cassier's  Jl/agaztne, 
PLATE  15.— Russian  Oil  Wells  at  Balakhani,  near  Baku. 


Photo,  F.  L.  Park  6-  Co.,  Los  Angeles. 

PLATE  16.— Oil  Wells  at  Los  Angeles,  California. 


ROMANCE  OF  THE  HYDROCARBONS   181 

sure  that  oil  is  also  present ;  and  accompanying  the  oil 
and  dissolved  in  it  are  solid  fatty  products  like  paraffin 
wax,  bitumen,  and  asphalt.  Vast  as  are  the  quantities  of 
gas,  the  quantities  of  oil  which  sometimes  accompany 
them  are  often  far  greater.  Oil  exists,  together  with  the 
gas,  often  under  enormous  pressure  deep  down  in  the 
earth.  Of  course  this  oil  is  extremely  valuable,  and  when 
a  region  is  suspected  of  containing  it  a  boring  is  made 
into  the  earth.  This  boring  is  carried  out  as  follows : 
First  a  wooden  structure,  called  a  derrick,  is  erected  over 
the  site  on  which  operations  are  to  be  commenced.  The 
derrick  is  usually  40  to  70  feet  high  and  is  for  supporting 
and  controlling  the  working  of  the  string  of  drilling  tools. 
The  drill  is  a  heavy  iron  chisel  known  as  a  "  bit,"  the 
weight  and  effective  striking  force  of  which  is  increased 
by  means  of  a  heavy  iron  bar  termed  a  "  sinker,"  to  which 
it  is  screwed.  This  combined  bit  and  sinker  is  suspended 
by  a  string  of  wooden  or  iron  poles  from  a  massive  beam 
of  wood  which  is  pivoted  at  its  centre  and  caused  to 
move  up  and  down,  like  a  see-saw,  by  means  of  an  engine. 
The  bit  is  thus  moved  up  and  then  down  rapidly  at  the 
rate  of  40-50  times  a  minute,  and  each  time  the  chisel, 
travelling  rapidly  with  the  weight  of  the  sinker  behind  it, 
strikes  the  bottom  it  plunges  into  the  rock  and  deepens 
the  hole.  The  whole  set  of  drilling  tools  may  weigh  a 
couple  of  tons  and  are  of  somewhat  complicated  design 
in  order  to  prevent  jamming,  but  we  cannot  describe 
them  here.1  Plates  15  and  16  show  typical  oil  wells. 

At  intervals  the  tools  are  withdrawn,  and  the  mud  and 
sand  produced  by  the  drilling  is  removed  by  pumps  or 
bailers.  As  the  well  is  sunk  it  is  cased  throughout  with 

1  The  reader  may  find  a  full  description  in  Trans.  Inst.  Mining  Engineers, 
vol.  35  (1907-1908),  p.  559,  "Notes  on  the  Winning  of  Crude  Oil,"  by  D.  M. 
Chambers.  See  also  "  The  Petroleum  Industry,"  by  George  Holloway,  "  Know- 
ledge," vol.  21  (1898),  pp.  124,  151,  169. 


1 82     MODERN  CHEMISTRY  AND  ITS  WONDERS 

iron  tubing  to  avoid  choking  up  by  detritus  or  caving-in 
of  the  strata.  Usually  when  oil  is  "  struck"  it  is  pumped 
out  to  the  surface  and  run  into  suitable  reservoirs.  But 
sometimes  the  drill  suddenly  penetrates  a  vast  reservoir  of 
underground  oil  in  a  highly  compressed  condition. 
When  this  happens  the  oil  rushes  out,  often  with  stupen- 
dous force,  and  rises  into  the  air  in  a  lofty  fountain. 
The  quantities  of  oil  which  have  thus  been  set  free  are 
almost  incredible.  Thus  in  1883  while  boring  for  oil  at 
Droojba  in  Baku,  oil  and  gas  came  suddenly  rushing  up 
the  bore  hole  with  irresistible  force,  hurled  the  drilling 
tools  weighing  some  tons  into  the  air,  crashed  with  a 
concussion  like  thunder  against  the  roof  and  sides  of 
the  wooden  structure  containing  the  boring  apparatus, 
shattered  them  in  an  instant,  then  burst  with  a  roar 
against  a  massive  beam  left  standing,  and  finally  squirted 
up  in  a  vast  fountain  eighteen  inches  in  diameter  to  the 
tremendous  height  of  300  feet,  and  falling  as  spray 
formed  great  lakes  of  oil  so  deep  that  a  boat  could  float 
on  them.  From  afar  this  mighty  pillar  capped  with 
falling  spray  presented  a  truly  wonderful  sight ;  it  towered 
aloft  like  a  huge  column  of  smoke  ascending  to  heaven, 
while  the  wind  catching  it,  carried  from  it  a  rain  of  oil 
which  drenched  the  whole  neighbourhood.  The  engineers 
were  absolutely  unprepared  for  such  a  vast  quantity  of 
oil,  and  had  no  means  for  storing  it.  Their  feelings  may 
be  imagined  when  they  saw  thousands  upon  thousands 
of  pounds'  worth  of  oil  simply  running  in  a  broad  river 
into  the  sea  !  When  after  about  three  months  the  well 
was  brought  under  control  and  capped  it  was  estimated  to 
have  yielded  half  a  million  tons  of  petroleum,  most  of 
which  was  lost.  The  well  poured  out  about  £11,000  worth 
of  oil  daily ! 

The  reader's  wonder  will  increase  when  he  learns  that 
this  is  by  no  means  the  largest  oil  flow  known.     Thus  at 


ROMANCE  OF  THE  HYDROCARBONS  183 


FIG.  15.— Oil  burst  at  Droojba  in  1883.     About  half  a  million  tons  of 
petroleum  were  lost. 


184     MODERN  CHEMISTRY  AND  ITS  WONDERS 

Bibi-Eibil  in  the  same  district  a  similar  outbreak  occurred ; 
the  whole  region  was  covered  with  oil,  cavities  in  the 
ground  being  converted  into  oil-lakes,  and  ten  million 
gallons  flowed  to  waste  in  the  Caspian  Sea.  In  1893  an 
oil  well  in  Baku  yielded  17,742  tons  of  oil  daily — a 
quantity  far  in  excess  of  the  Droojba  well. 

Great  quantities  of  sand  are  also  usually  thrown  up 
with  the  oil.  Thus  in  the  Droojba  oil  fountain  the  sand 
ejected  with  the  oil  half  buried  the  neighbouring  engine 
houses  and  workshops,  and  many  claims  for  damage  were 
put  in.  Another  well  struck  by  the  Mining  Company 
in  August  1887  not  only  threw  a  column  of  oil  12  inches 
in  diameter  to  a  height  of  200  feet  for  a  period  of  sixty- 
nine  days,  but  ejected  such  vast  quantities  of  sand  that 
some  one-story  stone  buildings  about  15  feet  high,  within 
100  yards  of  the  well,  were  actually  buried  out  of 
sight,  while  at  the  same  time  an  area  of  some  ten  acres 
around  the  well  was  covered  to  a  depth  of  from  1  to 
15  feet  with  sand!  Naturally  when  a  well  spouts  in  this 
way  a  great  waste  of  oil  is  almost  inevitable,  and  conse- 
quently the  engineers  endeavour  to  avoid  this  by  fitting 
the  metal  tube  coming  up  from  the  well  with  an  iron  cap 
with  a  gate  valve.  Often,  however,  the  pressure  exerted 
by  the  oil  is  so  immense  that  the  valves  and  strong  frame- 
work of  timbers  have  been  blown  away,  in  the  manner 
already  related.  Thorpe  relates  how  when  visiting  Baku 
in  1884  he  saw  one  of  Nobel's  capped  wells  flowing. 
Upon  opening  the  valve  the  fountain  rose  to  a  height  of 
100  feet  with  a  mighty  roar,  and  continued  to  flow  with 
undiminished  violence  until  the  valve  was  closed,  forming 
a  lake  of  oil  to  leeward  of  the  derrick. 

These  Russian  oil  fields  have  been  the  theatre  of  some 
terrible  disasters.  Thus  in  the  seventeenth  century  at 
Schemakla  an  earthquake  shock  shattered  the  town  and 
fissured  the  ground.  Evidently  it  ruptured  some  great 


ROMANCE  OF  THE  HYDROCARBONS   185 

subterranean  oil  reservoir,  for  from  out  of  the  fissures 
torrents  of  burning  oil  came  pouring,  flooding  the  district 
and  increasing  the  horrors  of  the  disaster.  But  the 
greatest  catastrophe  of  all  occurred  quite  recently,  in  the 
autumn  of  1905.  At  this  time  when  the  stir  and  unrest 
of  revolution  surged  and  ebbed  throughout  the  whole  of 
the  Russian  Empire,  the  workmen  of  Baku,  wild  savage 
men  from  Tartary,  rose  in  revolt,  fired  the  oil  wells,  slew 
the  overseers,  and  then  workless  and  homeless  marched  in 
thousands  over  the  terror-stricken  land,  burning  and 
plundering  as  they  went.  Out  of  3600  oil-wells  no 
less  than  3000  were  fired,  and  the  flames  and  smoke, 
shooting  upwards  in  vast  columns,  turned  night  into  day 
for  miles  around,  poisoning  the  air  with  dense  soot 
and  fumes.  Few  events  have  been  more  terrible  than 
this  uprising  ;  the  sudden  and  appalling  loss  of  millions 
of  money,  the  large  numbers  of  people  who  perished, 
coupled  with  the  almost  complete  ruin  of  a  great 
province,  profoundly  affected  the  imagination  of  the 
civilised  world. 

In  America  the  petroleum  industry  may  be  considered 
to  have  started  in  the  year  1859,  when  the  now  famous 
"  Colonel "  Drake  started,  amidst  general  hilarity,  to  drill 
for  oil,  at  Oil  Creek  in  Pennsylvania.  The  amusement 
with  which  the  public  followed  operations  suddenly 
turned  into  a  veritable  oil-fever  when  it  became  known 
that  he  had  succeeded  in  tapping  enormous  quantities  of 
oil.  Rapid  development  ensued  down  "  Oil  Creek  "  and 
along  the  Alleghany  River.  Over  two  million  barrels 
were  raised  in  1861  and  since  that  date  the  yield  has 
steadily  increased,  the  United  States  production  now  ex- 
ceeding 120  million  barrels. 

Indeed,  although  crude  oil  is  found  in  various  quarters 
of  the  world  at  the  present  day,  especially  in  Galicia,  yet  over 
90  per  cent,  of  the  whole  world's  supply  is  obtained  from 


i86     MODERN  CHEMISTRY  AND  ITS  WONDERS 

the  oil  fields  of  the  United  States  of  America  and  Russia. 
But  there  is  a  vast  difference  between  the  two  supplies. 
The  American  oil  fields  soon  run  out,  whereas  the  Russian 
appear  to  be  more  permanent.  In  consequence  of  this 
exhaustion  of  the  oil-bearing  district  in  America  great 
towns  containing  thousands  of  inhabitants  which  have 
sprung  up  in  the  midst  of  a  rich  oil-bearing  district,  bloom 
for  a  few  years,  and  then  in  consequence  of  the  exhaus- 
tion of  the  oil  vanish  almost  as  suddenly  as  they  arise. 
Fortunes  were  made  and  lost  with  extreme  rapidity  on 
these  oil  fields.  A  poor  man  would  in  consequence  of  a 
lucky  boring  suddenly  become  rich.  The  phrase  "to 
strike  oil  "  dates  from  this  period  of  intense  speculation 
and  activity. 

When  the  oil  stratum  is  struck,  or,  more  usually,  when 
the  well  begins  to  show  a  decreased  yield,  it  is  common 
in  America  to  explode  a  charge  of  dynamite — known  as 
"Torpedoing" — at  the  bottom  of  the  well  in  order  to 
loosen  the  soil  and  allow  the  oil  to  run  more  easily  into 
the  well. 

The  depths  of  oil-wells  vary  greatly.  Oil-wells  3000 
feet  deep  are  common.  Depths  of  nearly  4000  feet  are 
not  infrequently  met  with  in  Galicia,  and  these  with 
diameters  of  nearly  5  inches  at  the  bottom.  In  Russia 
the  wells  are  usually  shallower,  varying  from  700  to  1000 
feet,  though  deeper  wells  are  also  met  with.  In  Canada 
the  wells  average  1000-1500  feet,  in  Pennsylvania  2000- 
3000  feet.  Sometimes,  in  the  case  of  shallow  oil-wells, 
the  well  is  not  drilled  at  all,  but  a  shaft  is  dug  down  to 
the  oil-bearing  strata.  The  diggings  are  carried  on  by 
one  or  two  men  and  the  shaft  lined  with  timber  to  pre- 
vent caving  in.  As  the  depths  increase  it  is  generally 
found  that  poisonous  gas  issues  from  the  bottom  and 
a  stream  of  fresh  air  must  be  pumped  down  to  the  men 
below.  The  system,  however,  is  a  bad  one,  fatal  accidents 


ROMANCE  OF  THE  HYDROCARBONS   187 

as  the  result  of  earth-falls,  fire,  or  gas  poisoning  being 
common.  It  may  be  stated  here  that  the  gas  evolved 
from  petroleum  affects  its  victims  in  a  curious  way,  at 
first  making  them  intoxicated,  so  that  they  sing  and  dance 
in  a  frenzied  manner,  until  they  suddenly  collapse  ;  and 
when  once  this  happens  recovery  is  rare. 

The  oil  thus  produced  is  allowed  to  run  into  reser- 
voirs, whence  it  is  pumped  into  great  tanks  for  storage. 
Sometimes  these  tanks  are  about  90  feet  in  diameter  and 
30  feet  high,  giving  a  capacity  of  2500  tons  of  oil. 
But  sometimes  immense  oil-tanks  are  met  with,  which 
far  exceed  these  dimensions.  The  tanks  are  usually 
made  of  boiler-plate  and  are  roofed  over,  for  there  is 
always  a  danger  that  the  oil  may  become  ignited  by  a 
process  of  spontaneous  combustion  when  exposed  on  a 
hot  day  to  the  sun's  rays.  In  some  districts  earth-storage 
has  been  much  used,  reservoirs  being  excavated  and  lined 
with  wood  and  clay  and  covered  with  roofs  earthed  over. 
Such  tanks  are  indeed  the  safest.  In  America  the  intro- 
duction of  "  pipe-lines  "  has  been  brought  to  a  very  high 
state  of  perfection.  The  oil  is  pumped  direct  from  inland 
oil-producing  regions  through  hundreds  of  miles  of 
pipes  to  the  oil-refineries  situated,  usually,  on  the  sea- 
coast.  The  main  pipes  through  which  oil  is  pumped, 
often  as  far  as  100  miles  with  one  engine,  are  from  six 
to  eight  inches  in  diameter,  while  the  small  feed  lines 
which  pass  to  them  from  the  wells  are  about  two  inches 
in  diameter.  The  trunk  lines  are  made  of  welded 
wrought-iron,  tested  to  1500  Ibs.  the  square  inch,  the 
working  pressure  averaging  1000  Ibs.  The  lines  are  laid 
a  few  feet  below  the  surface  where  possible,  and  bends 
are  provided  for  expansion  and  contraction.  As  the  pipes 
are  liable  to  become  choked  by  dirt  or  solid  hydro-carbons, 
a  small  conical  steel  wire-brush,  known  as  a  "go  devil/' 
is  occasionally  passed  through  to  clear  them.  This  brush 


i88     MODERN  CHEMISTRY  AND  ITS  WONDERS 

travels  along  with  the  oil  as  the  latter  is  pumped  through 
the  pipes,  and  is  provided  with  ball  and  socket  joints,  to 
facilitate  its  progress  round  the  bends  ;  it  is  also  fitted 
with  vanes,  which  ensure  its  rotation  as  it  advances,  and 
it  has  at  the  end  a  stiffened  leather  base.  This  is  forced 
from  station  to  station  over  miles  of  country,  and  is 
followed  by  men  on  foot  or  horseback,  who  keep  within 
hearing  of  the  whirring  noise  of  the  instrument,  and  in 
case  of  stoppage  must  locate  the  spot  so  as  to  be  able  to 
clear  the  obstructed  section. 

The  pumps  now  invariably  used  for  these  lines  are 
of  the  Worthington  type,  and  work  at  a  pressure  which 
sometimes  rises  as  high  as  1500  Ibs.  per  square  inch.  The 
760  miles'  length  of  six-inch  pipe  extending  along  the 
New  York  line  is  worked  by  pumps  of  from  600  to  800 
horse-power,  and  conveys  about  30,000  gallons  daily.  Of 
course  on  a  long  line  like  this  the  relay  system  is  em- 
ployed. There  are  eleven  pumping  stations,  each  with  a 
pump-house  and  two  or  more  tanks.  Each  well-owner, 
as  his  oil  is  passed  into  the  pipes,  receives  a  certificate 
stating  that  he  is  entitled  to  so  much  oil,  and  these  cer- 
tificates are  negotiable  like  banknotes  among  those  in  the 
trade.  Of  course  all  the  oil  passes  into  the  common  re- 
servoir, so  that  no  producer  can  receive  his  own  oil  from 
the  refinery. 

In  other  countries  other  means  of  transport  are  used, 
the  most  common  being  railway  tanks.  These  are  cylin- 
drical tanks  of  boiler-plate,  provided  with  a  dome  through 
which  they  are  filled  and  a  valve  underneath  for  outlet. 
These  are  to  be  seen  on  all  railways.  Where  possible, 
water-transport  is  made  use  of.  Tank-barges  100—150 
feet  long,  of  20  feet  beam,  divided  into  a  series  of  com- 
partments by  oil-tight  bulk-heads,  provide  a  convenient 
transporting  medium. 

For  ocean  transport  the  oil  is  now  usually  conveyed 


ROMANCE  OF  THE  HYDROCARBONS   189 

in  tank-steamers,  in  which  the  whole  hold  is  formed  in 
compartments  or  tanks  to  contain  the  oil.  In  order  to 
prevent  injury  to  the  vessel  from  the  oil  rolling  about  in 
bad  weather,  the  tanks  are  kept  quite  full,  small  auxiliary 
"  expansion  tanks  "  being  fitted  to  receive  any  overflow 
when  an  increase  of  temperature  causes  the  oil  to  expand, 
or  to  supply  oil  to  the  main  tank  when  a  contraction  in 
volume  occurs.  In  earlier  days  the  escape  of  gas  and 
inflammable  vapour  from  the  oil  led  to  terrible  ex- 
plosions, which  occasioned  great  loss  of  life.  But  the 
ventilation  is  now  so  perfect  that  the  danger  is  greatly 
minimised. 

However,  even  at  the  present  time,  the  dangers  of 
oil  transport  at  sea  have  not  been  entirely  overcome, 
and  so  recently  as  27th  April  1914  a  Russian  oil-ship, 
carrying  a  cargo  of  petrol  to  Rouen,  blew  up  off  Algiers 
late  on  a  Sunday  night.  Of  thirty  persons  on  board 
fifteen  lost  their  lives.  The  captain's  wife,  who  was  on 
board  at  the  time  of  the  explosion,  swam  for  two  hours 
in  the  sea  at  night  in  danger  of  being  overtaken  by  a 
flood  of  burning  oil.  "  My  husband  put  me  into  a  boat 
after  the  ship  had  burst  into  flames,"  she  said,  "  but  it 
capsized.  I  found  myself  swimming  in  the  black  water, 
which  was  lit  up  by  the  flames  from  the  burning  ship. 
The  oil  spread  on  the  sea  and  formed  one  vast  burning 
film  which  the  wind  drove  towards  me.  For  two  hours 
I  swam  frantically  from  the  flames. 

"  Just  as  I,  exhausted,  was  about  to  give  up  the  struggle, 
I  heard  a  voice  shouting  in  Russian,  '  Come  here.'  It 
was  the  chief  stoker  of  the  vessel,  together  with  a  number 
of  the  crew,  in  a  boat  nearly  full  of  water.  I  was  hoisted 
into  it,  and  sat  for  two  hours  up  to  my  hips  in  water, 
until  at  last  we  were  saved." 

As  we  have  already  remarked,  gas  invariably  accom- 
panies the  oil,  being  dissolved  in  it,  and  is,  as  we  shall 


MODERN  CHEMISTRY  AND  ITS  WONDERS 

see,  only  the  more  volatile  products  of  the  crude  petroleum  ; 
even  on  the  oil  fields  itself  it  is  the  source  of  danger,  on 
account  of  its  being  highly  inflammable  and  when  mixed 
with  air  violently  explosive.  Nearly  all  the  fires,  often  at- 
tended with  considerable  loss  of  life,  which  sooner  or  later 
visit  all  oil  fields,  are  attributable  to  this  gas  ;  and  the 
strictest  regulations  regarding  the  use  of  lights,  smoking, 
and  the  situation  of  boiler-houses  with  regard  to  the  wells, 
are  in  force.  Many  a  workman,  with  the  intention  of 
having  a  quiet  smoke  unknown  to  the  authorities,  has 
struck  a  match  and  been  promptly  hurled  to  his  death  by 
a  great  gas  explosion,  which  has  been  known  to  wreck 
the  great  oil  tanks,  and  scatter  a  flood  of  blazing  oil 
around,  causing  the  most  frightful  damage  and  loss  of 
life.  Plate  17  shows  an  oil-well  on  fire. 

Having  arrived  at  the  refineries,  the  oils  are  subjected 
to  a  process  of  fractional  distillation.  Since  petroleum  is 
a  mixture  of  compounds  of  carbon  and  hydrogen  of 
different  volatility,  this  process  separates  it  into  a  number 
of  products  of  different  boiling  points. 

For  this  purpose  various  types  of  still  have  been 
devised,  the  Russians  largely  using  the  tl  Continuous  Still," 
in  which  the  crude  oil  is  supplied  as  fast  as  the  distillate 
passes  off.  For  American  petroleum,  however,  non- 
continuous  stills  work  best.  These  are  cooled  down  and 
the  residue  removed  after  each  distillation.  In  distilling 
petroleum  some  of  the  constituents  are  decomposed 
into  other  bodies,  which  are  often  more  volatile  than  the 
bodies  producing  them.  In  what  is  known  as  the 
"  Cracking  process "  this  decomposition  is  caused  to  be 
increased  by  allowing  a  portion  of  the  distillate  to  con- 
dense on  the  cooler  upper  region  of  the  still,  and  run  back 
upon  the  hotter  liquid  at  the  bottom.  This  action,  how- 
ever, is  not  allowed  to  take  place  until  the  bulk  of  the 
lighter  oils  have  been  distilled  off,  as  it  is  the  heavier  and 


f 


From  Cassier's  Magazine, 


PLATE  17.—  Russian  Oil  Well  on  Fire. 

Russian  oil  wells  often  spontaneously  take  fire  and  burn  furiously, 
causing  great  damage  and  loss  of  property. 


ROMANCE  OF  THE  HYDROCARBONS   191 

less  valuable  constituents  of  the  petroleum  which  it  is 
desired  to  decompose,  in  order  that  a  maximum  of  illum- 
inating oil  may  be  obtained. 

The  stills  themselves  are  great  iron  vessels,  30  feet 
and  more  in  length,  and  of  a  corresponding  breadth  and 
diameter.  They  are  heated  by  furnaces  underneath,  and 
hold  from  600  to  1200  barrels  of  oil.  From  the  stills 
there  passes  out  an  elaborate  series  of  condensing  coils, 
cooled  by  water,  which  deliver  the  distilled  petroleum 
into  box-like  receptacles  with  plate-glass  sides,  through 
which  the  runnings  of  the  distillate  can  be  observed,  and 
a  test  sample  withdrawn  from  time  to  time. 

The  distillate  is  agitated  with  sulphuric  acid,  followed 
by  treatment  with  caustic  soda,  and  then  washing  with 
water,  which  is  drawn  off  after  settlement. 

Naturally  the  chemical  constitution  of  these  oils 
aroused  the  curiosity  of  chemists,  and  their  systematic 
investigation  brought  to  light  an  immense  number  of 
new  compounds  composed  of  carbon  and  hydrogen 
(hydrocarbons). 

These  natural  hydrocarbons  belong  to  three  different 
categories,  typified  by  the  petroleum  of  Pennsylvania,  the 
Caucasus,  and  Galicia  respectively.  The  American  oil 
chiefly  consists  of  compounds  belonging  to  the  ft  Paraffin  " 
series  of  hydrocarbons,  which  possess  the  formula 
CwH2w+2,  where  n  varies  from  1  up  to  a  very  large 
number.  The  Baku  oil  consists  of  compounds  belong- 
ing to  the  Olefine  series,  which  have  the  formula  Cnli2n. 
The  oil  of  Galicia  includes  hydrocarbons  of  both 
series,  together  with  aromatic  compounds  derived 
from  benzene,  corresponding  to  the  general  formula 

C«H2«-6' 

The  gases  which  accompany  the  oils  and  stream  out 
of  the  earth  in  the  wonderful  manner  already  described, 
are  the  compounds  of  the  series  which  possess  the  lightest 


192      MODERN  CHEMISTRY  AND  ITS  WONDERS 

molecules,    and    therefore    are    the    most   volatile.      Fr 
example,    Methane,   or   marsh    gas,   CH4,  obtained    fr 
the    general  formula  C^H2w  +  2  by  putting  n=l,  Etha 
C2H6    (w  =  2),    Propane,    C3Hg    (*  =  3),    Ethylene,    C2K 
(n  =  2  in  the  series  CWH2W),  &c.  &c. 

The  liquid  parts  consist  of  more  complex  com- 
pounds, such  as  C4H1Q  (Butane),  C5H12  (Pentane),  CgH14 
(Hexane),  &c.  &c. 

The  solid  parts  consist  of  immensely  complex  mole- 
cules, containing  sixty  and  more  carbon  atoms  united 
together. 

When  these  natural  oils  are  distilled,  the  boiling  point 
of  the  vapours  constantly  changes,  beginning  at  0°  C.  and 
going  up  to  above  350°. 

That  part  of  the  oil  which  distils  over  first  is  a 
very  mobile,  colourless  liquid,  from  which  the  hydro- 
carbons which  boil  at  low  temperatures  may  be  extracted 
—namely,  C4H1Q,  C5H]2  (which  boil  about  30°  C.),  C6H14 
(which  boils  at  62°  C.),  C7H16  (boiling  point,  90°  C.); 
&c.  &c. 

That  part  of  the  petroleum  distillate  which  boils  above 
130°  C.  and  contains  the  hydrocarbons  C9H2Q,  C1QH22, 
CnH24,  forms  the  oily  substance  used  for  lighting 
(kerosene).  Those  portions  which  are  still  more  complex 
and  boil  between  275°  C.  and  300°  C.  form  an  excellent 
oil  for  illuminating  purposes,  but  can  only  be  distilled 
without  change  by  means  of  superheated  steam ;  other- 
wise they  are  largely  decomposed. 

Parts  of  still  higher  boiling  points  form  lubricating  or 
machine  oils.  While  vaseline  is  a  semi-fluid  mass  of  still 
higher  boiling  point.  The  waste  fluid  masses  which 
cannot  be  profitably  distilled  are  used  instead  of  coal  as 
a  liquid  fuel. 

By  systematic  researches  these  different  hydrocarbons 
have,  as  already  related,  been  classed  in  three  groups, 


ROMANCE  OF  THE  HYDROCARBONS   193 

""'h   one   of   which   can    be    represented    by    a    general 

>  ula  : 
i 
f      GROUP  I.  GROUP  II.  GROUP  III. 

The  Paraffins,  The  Olefmes,          Unsaturated  compounds, 

CnH2n+2  CnH2u  C,,H2n_2 

Methane,  CH4 

Ethane,  C2H6  Ethylene,  C2H4  Acetylene,  C2H2 

Propane,  C3H8  Propylene,  C3H6  Propine,  C3H4 

Butane,  C4H10  Butylene,  C4H8  Butine,  C4H6 

Pentane,  C6H12  Pentylene,  C6H10  Pentine,  C6H8 
&c.                                   &c.  &c. 

Those  hydrocarbons  classed  under  Group  III  are 
so  unstable  that  they  hardly  occur  at  all  naturally.  But 
a  fourth  series  of  hydrocarbons  occurs  which  are  of  an 
entirely  different  type.  In  them  the  carbon  atoms  are 
united  together  to  form  tiny  rings  or  chains,  and  they 
are  known  as  "  aromatic  "  compounds.  The  most  im- 
portant member,  benzene,  C6H6,  contains  a  closed  chain 
of  six  carbon  atoms,  its  constitution  being  represented 
as  follows  : 

CH 


HC         CH 

I        II 
HC        CH 

v 

CH 

This  body,  and  analogues  of  it,  like  toluene,  naphthalene, 
anthracene,  occur  largely  in  the  liquids  obtained  from 
coal  when  this  is  distilled  in  gas-making.  From  it  are 
made  innumerable  numbers  of  those  beautiful  and  delicate 
dyes,  medicines,  and  scenty  matters,  which  are  now  so 
famous  throughout  the  world. 

When  oil  evaporates  it  leaves  behind  solid  matter  like 
asphalt,  paraffin,  and  pitch.  It  was  with  this  asphalt  that 

N 


194     MODERN  CHEMISTRY  AND  ITS  WONDERS 

the  inhabitants  of  Nineveh  paved  their  streets  some  four 
thousand  years  ago — just  as  we  do  now  —  and  used  it 
as  a  mortar  for  building  houses.  There  is  an  island  on 
the  eastern  side  of  the  Caspian  Sea  called  Tcheliken, 
where  the  very  cliffs  are  composed  of  crude  paraffin  wax, 
called  "  Ozokerite " ;  while  east  of  Krasnovodsk,  on 
the  same  shore,  "  there  are  immense  hills  of  ozokerite  and 
petroleum."  These  must  have  been  produced  in  pre- 
historic times  by  vast  quantities  of  oil  rushing  out  of  the 
earth  and  evaporating  away,  leaving  behind  them  these 
solid  residues.  The  most  remarkable  deposit  of  pitch  or 
bitumen  in  the  world  is  the  celebrated  "  Great  Pitch 
Lake"  of  Trinidad  (Plate  18).  It  is  a  mile  and  a  half 
in  circumference,  and  covers  137  acres.  The  bitumen  is 
solid  and  cold  near  the  shores,  but  gradually  increases 
in  temperature  and  softness  towards  the  centre.  Men 
and  animals  are  stated  to  have  been  lost  in  the  pitch  by 
venturing  too  far  out  on  to  the  lake.  The  ascent  from 
the  lake  to  the  sea,  a  distance  of  three-quarters  of  a  mile,  is 
covered  with  hardened  pitch,  on  which  trees  and  vegetables 
flourish.  Naturally  this  vast  accumulation  of  asphalt  has 
not  escaped  the  keen  eye  of  the  mineral  exploiter,  and  the 
lake  is  now  being  mined.  Between  1893  and  1906  no 
less  than  1J  million  tons  of  the  mineral  have  been  re- 
moved and  exported  for  making  roads,  pavements,  and 
other  purposes.  The  supply  is  said  to  be  inexhaustible, 
and  a  boring  near  the  centre  reached  a  depth  of  135  feet 
without  touching  bottom.  Nevertheless,  in  consequence 
of  excavation,  the  surface  of  the  lake  has  fallen  a  distance 
of  7'1  feet  between  the  years  1893  and  1906.  The  pitch, 
in  fact,  acts  as  a  very  slow  flowing  fluid,  and  tends  to  fill 
up  cavities  made  in  it.  Indeed,  the  natural  level  of  the 
deposit  is  assumed  in  a  day  or  so  after  the  removal  of 
the  pitch,  and  so  the  digging  goes  forward  almost  con- 
tinuously in  the  same  spot.  In  the  course  of  ages  the 


PLATE  18. — Great  Pitch  Lake  at  Trinidad. 
Showing  the  pitch  being  excavated  and  loaded  into  trucks. 


PLATE  19. — Village  of  La  Brea,  Trinidad. 
This  is  built  on  pitch,  which  is  shown  being  dug  out  by  negro  workmen. 


ROMANCE  OF  THE  HYDROCARBONS   195 

pitch  from  the  lake  has  overflown  and  filled  a  narrow 
ravine  running  in  a  northerly  direction,  and  upon  this 
deposit  in  the  course  of  time  the  village  of  La  Brea  has 
sprung  up  (Plate  19).  The  villagers  are  engaged  in  break- 
ing up  and  excavating  this  pitch  deposit,  which  covers 
an  area  of  some  seventy  acres.  The  lake  itself  presents 
the  appearance  of  a  dark  pavement,  with  natural  furrows 
running  in  every  direction,  forming  watercourses,  from 
which  the  surface  drainage  extends  to  an  artificial  outlet 
cut  in  the  rim  of  the  lake.  The  surrounding  margin  of 
the  lake  is  covered  with  rank  grasses  and  palmetto  of 
a  luxuriant  type,  and  small  islands,  dotted  here  and  there, 
maintain  a  similar  vegetation.  These  so-called  floating 
islands  have  been  formed  either  by  the  accumulation  of 
wind-blown  material,  or  from  detached  portions  of  the 
sides  finding  their  way,  by  the  action  of  convection 
currents  in  the  viscid  pitch,  into  different  parts  of  the 
area.  Such  flows  can  be  traced  at  the  present  time,  and 
these  islands  are  gradually  moving  to  the  seat  of  active 
excavation.  The  lake  is  believed  to  have  been  formed 
by  oil  flowing  for  ages  from  out  of  the  earth,  evaporat- 
ing away,  and  leaving  the  solid  non-volatile  products, 
which  oxidised  to  form  the  bitumen. 

Mr.  Beeby  Thompson  calculates  that  there  must  be 
at  least  10,000,000  tons  of  pitch  in  these  deposits  at  the 
present  time,  and  this  represents  the  residue  left  from 
the  evaporation  of  40,000,000  tons  of  oil!  As  the  total 
oil-production  in  the  world  is  26,000,000  tons,  the  reader 
can  form  a  faint  idea  of  the  immense  quantity  of  oil  which 
has  been  used  in  the  formation  of  the  lake.1 

The  theories  to  account  for  the  formation  of  petroleum 

1  The  reader  will  find  a  full  account  of  these  wonderful  deposits  in  a  valu- 
able paper  (and  discussion)  in  the  Transactions  of  the  Institution  of  Mining 
Engineers,  vol.  xxxv  (1907-1908),  p.  453,  entitled  "The  Mineral  Resources  of 
Trinidad,"  by  John  Cadman,  M.Sc. 


196     MODERN    CHEMISTRY  AND  ITS  WONDERS 

are  many  and  various.  They  may  however  be  divided 
under  two  heads,  namely,  those  which  derive  it  from  the 
decomposition  of  animal  or  vegetable  matter,  and  those 
which  attribute  it  to  purely  inorganic  chemical  action. 
Everyone  knows  that  in  marshes  decaying  vegetable 
matter  gives  off  "  marsh  gas,"  which  is  the  same  gas  which 
accompanies  oil  deposits,  and  is  produced  by  the  action 
of  certain  minute  organisms  on  woody  fibre.  Now  this 
marsh  gas  is  the  first  term  of  the  hydrocarbons  of  which 
petroleum  is  composed,  and  many  authors  believe  that 
vast  quantities  of  animal  and  vegetable  matter  decom- 
posing under  certain  conditions,  possibly  under  bacterial 
action,  have  given  rise  to  oil  instead  of  passing  into  coal, 
which  also  may  be  looked  upon  as  a  highly  carbonised 
hydrocarbon.  Oils  are  usually  found  in  formations  whose 
geological  character  shows  them  to  have  been  at  one  time 
the  bed  of  a  salt  marsh  or  salt  inland  sea,  and  it  is  believed 
that  it  was  the  remains  of  untold  millions  of  sea  animals, 
such  as  fishes  and  sea-plants,  but  principally  minute  micro- 
organisms such  as  now  swarm  in  certain  gulfs  and  along 
certain  seashores,  as  well  as  in  larger  pelagic  areas,  such 
as  the  Caspian  and  Sea  of  Aral,  which  mingled  with  clay 
and  sand  formed  in  the  course  of  time  vast  deposits 
of  black  mud,  and  ultimately  passed  into  oil.  So  that 
the  oil  we  now  burn  in  our  lamps  may  have  come  from 
the  bodies  of  live  animals  which  lived  millions  of  years  ago, 
in  a  strange  world  in  which  we  should  recognise  scarcely 
any  resemblance  to  our  modern  one.  A  certain  amount 
of  oil  is  often  met  with  in  coal  seams,  which  are  un- 
doubtedly of  vegetable  origin,  and  this  has  been  held  to 
confirm  the  organic  origin  of  petroleum. 

The  inorganic  theory  to  account  for  the  formation  of 
petroleum  considers  that  it  is  formed  by  water  coming 
into  contact  with  metallic  carbides  in  the  interior  of  the 
earth.  It  decomposes  them,  yielding  various  gaseous, 


ROMANCE  OF  THE  HYDROCARBONS  197 

liquid  and  solid  hydrocarbons,  which  constitute  petroleum. 
Moissan,  Berthelot,  and  Mendeleeff  have  made  many  ex- 
periments to  prove  that  this  is  possible.  Thus,  aluminium 
carbide,  C3A14,  in  contact  with  water  yields  methane  and 
aluminium  hydrate : — 

C3A14         +12H20  =          3CH4          +     4A1(OH)3 

Aluminium  carbide          Water  Methane  or  marsh  gas      Aluminium  hydrate 

Other  carbides,  for  example  uranium  carbide,  yield 
solid  and  liquid  hydrocarbons.  Mendeleeff  has  shown 
that  iron  rich  in  carbon  does  actually  yield,  when  treated 
with  acids,  a  liquid  mixture  of  hydrocarbons  exactly 
similar  to  mineral  naphtha  in  taste,  smell,  and  reaction. 
Since  very  hot  water  under  a  great  pressure,  such  as  exists 
in  the  earth,  behaves  as  a  strong  acid,  and  since  we  have 
every  reason  to  believe  that  both  metals  and  metallic 
carbides  exist  deep  down  in  the  earth's  interior,  and  since 
we  have  abundant  proof  that  water  does  penetrate  to  such 
white  hot  regions — vast  clouds  of  steam  are  daily  ejected 
by  all  volcanoes — we  have  good  reason  to  believe  that 
some  at  least  of  the  petroleum  found  upon  the  earth  is 
derived  from  this  source.  "  Although  the  inorganic- 
origin  theory  to-day  perhaps  only  counts  comparatively 
few  supporters,  yet  they  can  boast  of  world-famed  names 
among  their  ranks,  as  also  that  their  opponents  have  never 
yet  been  able  to  explain  satisfactorily  both  the  evident  re- 
lation of  vulcanism  and  petroleum,  and  much  less  the 
enormous  quantities  of  the  mineral  accumulated  in  com- 
paratively small  areas."  l 

Sabatier  has  recently  carried  out  some  experiments 
which  lead  him  to  conclude  that  petroleum  is  formed  in 
the  earth  as  the  result  of  the  action  of  acetylene  gas  and 
hydrogen  on  the  iron,  nickel,  and  cobalt.2 

1  Dr.  Sandberg,  Trans.  Inst.  Mining  Engineers >  1907-8,  vol.  xxxv,  p.  546. 

2  Loc.  cit.t  p.  708. 


198     MODERN  CHEMISTRY  AND   ITS  WONDERS 

Possibly  since  different  oils  have  different  chemical 
compositions,  they  have  been  formed  in  different  ways. 

We  have  already  described  how  a  gas  called  methane 
or  marsh  gas  (CH4)  rushes  out  of  the  ground  in  oil-dis- 
tricts. We  will  now  give  a  fuller  account  of  it. 

Marsh  gas,  as  its  name  denotes,  is  evolved  from  marshy 
districts,  where  it  forms  part  of  the  ghostly  flames  which 
form  the  "  Will-o'-the-wisp  "  or  "  Corpse  Light,"  to  which 
so  many  terrible  legends  are  attached.  (Plate  20.) 

The  Will-o'-the-wisp  is  now  never  seen  in  England, 
owing  to  extensive  drainage.  But  formerly  it  was  fre- 
quently met  with.  Thus,  so  recently  as  1855,  two 
travellers  were  crossing  the  moors  between  Hexham  and 
Alston,  about  ten  o'clock  at  night,  when  they  were  startled 
by  the  sudden  appearance  of  a  light  close  to  the  roadside, 
about  the  size  of  a  man's  hand,  and  of  an  oval  shape. 
The  light  was  about  three  feet  from  the  ground,  hovering . 
over  moist  peat  holes,  and  it  moved  nearly  parallel  with 
the  road  for  about  50  yards,  when  it  vanished.  In  old 
times  flames  were  often  seen  to  hover  over  places  where 
large  numbers  of  men  were  buried,  such  as  battlefields  or 
graveyards,  and  hence  the  legend  indicated  in  the  lines  of 
the  old  rhyme : 

"  Where  corpse-light  dances  bright, 
Be  it  day  or  night, 
Be  it  light  or  dark, 
There  shall  corpse  lie  stiff  and  stark." 

The  inflammable  gases  (probably  containing  phos- 
phoretted  hydrogen)  in  this  case  arose  from  decomposing 
animal  matter. 

These  wandering  lights  were  formerly  a  source  of 
terror  to  the  ignorant,  and  have  often  led  travellers  who 
have  lost  their  way  at  night  into  dangerous  bogs,  thinking 
that  the  light  proceeded  from  some  cottage,  or  was  carried 


ROMANCE    OF    THE    HYDROCARBONS     199 

by  a  man,  a  state  of  affairs  described  in  the  well-known 
lines : 

"Drear  is  the  state  of  the  benighted  wretch, 
Who  then,  bewildered,  wanders  through  the  dark, 
Full  of  pale  fancies,  and  chimeras  huge ; 
Nor  visited  by  one  directive  ray, 
From  cottage  streaming  or  from  airy  hall. 
Perhaps  impatient  as  he  stumbles  on, 
Struck  from  the  root  of  slimy  rushes,  blue, 
The  wild-fire  scatters  round,  or  gathered,  trails 
A  length  of  flame  deceitful  o'er  the  moss  : 
Whither  decoy'd  by  the  fantastic  blaze, 
Now  lost  and  now  renew'd,  he  sinks  absorbed, 
Rider  and  horse,  amid  the  miry  gulf; 
While  still,  from  day  to  day,  his  pining  wife 
And  plaintive  children  his  return  await, 
In  wild  conjecture  lost." 

Marsh  gas,  in  boggy  districts,  is  being  ceaselessly 
formed  by  a  process  of  fermentation  of  cellulose  or  plant 
fibre  by  micro-organisms.  Its  formation  can  be  easily 
imitated  by  placing  paper  or  wood  in  a  flask  filled  quite 
full  of  water,  then  placing  in  it  some  river  mud  which 
contains  the  organism,  and  allowing  the  whole  to  stand 
for  some  days.  Gas  will  be  evolved  and,  if  the  flask  be 
provided  with  a  glass  leading  tube,  may  be  collected  in 
a  glass  jar  filled  with  water  in  the  same  manner  as 
hydrogen  gas. 

The  gas  thus  obtained  will  be  found  to  be  colourless, 
invisible,  and  devoid  of  smell.  It  much  resembles 
hydrogen,  being  light,  and  burning  with  a  pale  blue 
flame,  forming  carbon  dioxide  and  steam : 

CH4  +  202   =        C02       +2H20 

Methane  or  marsh  gas       Oxygen      Carbon  dioxide        Steam 

If  mixed  with  twice  its  volume  of  oxygen  or  with  ten 


200      MODERN   CHEMISTRY  AND   ITS  WONDERS 

times  its  volume  of  air  (which  contains  two  volumes  of 
oxygen)  the  gas  explodes  with  great  violence.  This  pro- 
perty has  been  the  cause  of  many  terrible  mining  accidents. 
For  the  gas  occurs  stored  up  in  coal,  being  probably 
formed  by  a  slow  process  of  decomposition  going  on  in 
this  mineral  at  ordinary  temperatures.  Reservoirs  of  the 
gas  in  a  highly  compressed  condition  are  thus  gradually 
pent  up  in  minute  cavities,  and  from  these  it  continually 
streams  out  into  the  mine.  Hence  besides  the  danger  of 
being  crushed  to  death  by  a  fall  of  rock,  or  immured  in  a 
living  tomb  by  an  irruption  of  water,  or  a  fall  of  rock, 
the  miner  has  another  and  often  more  dangerous  enemy 
to  encounter  in  the  noxious  gases  evolved  in  coal  pits. 

Consequently  in  all  modern  coal  mines  the  greatest 
attention  is  paid  to  ventilation.  By  means  of  huge  pump- 
ing engines  a  stream  of  fresh  air  is  sent  rushing  through 
every  part  of  the  mine,  and  thus  sweeps  away  the  gas  as 
fast  as  it  is  evolved.  We  may  form  some  idea  of  the 
amount  of  air  thus  forced  in  when  we  learn  that  in  many 
collieries  the  ventilating  current  exceeds  500,000  cubic 
feet  of  air  per  minute,  sweeping  through  miles  of  galleries 
at  the  rate  of  eighteen  to  twenty  feet  a  second.  The 
quantity  of  methane  ("  fire-damp  "  is  the  name  given  to  it 
by  miners :  damp  corresponds  to  German  "  Dampf," 
vapour)  which  is  poured  into  the  workings  of  some  mines 
is  very  large  and  continually  varying.  Some  seams  of 
coal  contain  much  more  than  others,  and  it  is  not  un- 
common for  a  jet  of  gas  to  rush  out  of  every  hole  made 
in  the  seam.  Thus  in  the  celebrated  Wallsend  Colliery  an 
attempt  was  made  to  work  one  of  the  fiery  seams,  and  re- 
sulted in  a  terrible  disaster.  In  his  evidence  before  a 
committee  of  the  House  of  Commons  Mr.  Buddie  said,  "  I 
simply  drilled  a  hole  into  the  solid  coal,  stuck  a  tin  pipe 
into  the  aperture,  surrounded  it  with  clay,  and  lighted  it. 
I  had  immediately  a  gas-light.  The  quantity  evolved  from 


ROMANCE    OF    THE    HYDROCARBONS      201 

the  coal  was  such  that  in  every  one  of  those  places  I  had 
nothing  to  do  but  to  apply  a  candle,  and  then  could  set  a 
thousand  pipes  on  fire.  The  whole  face  of  the  working 
was  a  gas  pipe  from  every  pore  of  coal."  Sometimes  the 
gas  bursts  suddenly  forth  from  the  coal  with  a  noise  like 
that  of  rushing  waters,  or  the  roar  of  a  blast  furnace. 
These  local  outbursts  are  called  "blowers."  In  a  single 
minute  they  have  been  known  to  fill  the  mine  for  1000 
feet  with  an  explosive  mixture  of  gas  and  air.  They  are 
not  merely  dangerous  from  their  inflammable  vapours,  but 
also  from  the  pieces  of  coal  which  the  escaping  gas  forces 
from  the  roof,  and  whose  fall  maims  or  kills  the  un- 
fortunate miners  beneath.  As  may  be  easily  imagined, 
old  workings  or  abandoned  mines  often  get  filled  with  the 
gas,  and  thus  become  very  dangerous  to  adjacent  workings 
unless  they  are  completely  isolated  by  stone  walls.  The 
immense  quantity  of  gas  which  was  emitted  by  an 
abandoned  part  of  the  Wallsend  coal  pit  affords  a  striking 
example  of  the  danger  of  such  an  accumulation.  A  four- 
inch  pipe  was  passed  from  the  bottom  of  the  mine  to  a  few 
feet  above  the  surface  of  the  ground.  When  a  light  was 
brought  near  a  hissing  flame  roared  aloft  and  burnt  night 
and  day  for  a  long  time.  The  pipe  poured  out  in  stream- 
ing flame  thousands  upon  thousands  of  cubic  feet  of 
escaping  gas — enough  to  illuminate  a  little  town. 

The  results  of  a  great  methane  explosion  in  a  mine 
are  indeed  terrible.  Three  or  four  cubic  inches  of  the 
gas  when  mixed  with  air  and  ignited  detonate  like  a 
pistol  shot.  A  cubic  foot  of  the  mixture  enclosed  in  a 
bottle  and  exploded  will  shatter  the  glass,  bursting  it 
like  an  exploding  shell.  Judge  then  how  terrific  are  the 
effects  when  tens  of  thousands  of  cubic  feet  in  the 
galleries  of  a  mine  explode  because  a  miner  incautiously 
strikes  a  match,  or  the  flame  of  a  safety  lamp  passes 
through  the  gauze  which  surrounds  it.  The  explosion  of 


202      MODERN   CHEMISTRY  AND   ITS  WONDERS 

a  large  subterranean  powder  magazine  would  not  be  more 
terrific.  A  thundering  flame  flashes  through  the  tunnels 
of  the  mine.  It  comes  out  of  the  darkness  with  a  roar 
and  flies  down  the  main  roadways  with  a  velocity  far 
swifter  than  that  of  the  swiftest  railway  train.1  The  flame 
gradually  gathers  volume  and  speed,  the  narrow  walls 
become  too  small  for  the  rush  of  expanding  gas.  The 
side  walls  crumble  and  burst  under  the  sudden  strain, 
while  the  ground  rocks  and  throws  men  off  their  feet. 
Every  man  and  boy  in  the  pit  is  stricken  cold  to  the 
heart  at  the  first  murmur  of  the  rolling  thunder ;  for  they 
know  that  it  is  the  roar  of  oncoming  death.  Even  the 
horses,  and  there  are  hundreds  of  them  in  every  large 
mine,  know  why  the  walls  and  ground  shake  and  vibrate, 
and  in  wild  confusion  men,  boys,  and  horses  rush  out 
into  the  main  roadway.  The  only  hope  of  escape  is  to 
get  to  the  shaft,  far  away  down  the  main  artery.  As  they 
turn  the  corner  of  their  little  sideroads  and  reach  the 
main  roadway  they  see  the  fire  rushing  down  upon  them, 
filling  the  whole  road,  a  great  river  of  red,  blue,  and 
green — for  the  dust  and  gases  of  the  shattering  roads 
give  it  strange  colours.  They  fly  before  it,  horses,  men, 
and  boys,  shouting,  screaming,  tumbling  one  over  the 
other  in  the  narrow  passage.  The  flame  comes  on  swifter 
than  they  can  run  ;  it  reaches  them  ;  its  strength  is 
demoniacal.  It  catches  them  up  like  straws  in  a  wind  and 
horses,  trams,  men,  and  boys  are  swept  before  it,  being 
shattered  to  pieces  against  the  rugged  sides  of  the  mine, 
and  crushed  into  one  great  heap  of  wreckage.  Very 
often,  however,  especially  in  the  old  days,  the  methane 
burns  quietly  along  the  roofs  of  the  tunnels  without 
causing  explosion  at  all.  A  remarkable  scene  of  this 

1  Some  recent  experiments  by  Dr.  Garforth  showed  that  the  explosive  wave 
can  travel  at  the  enormous  speed  of  1300  miles  per  hour!  See  Jr.  Soc.  Chem> 
Ind.,  July  15,  1913,  p.  687. 


ROMANCE  OF  THE  HYDROCARBONS  203 

kind  was  experienced  by  Kingsley.1  He  had  been 
visiting  a  mine  to  see  the  sights,  and  he  thus  describes 
the  event :  "  I  might  have  been  twenty  paces  behind  the 
rest  of  the  party  when  a  sudden  light  started  up  among 
them — I  can  compare  it  to  nothing  but  a  flash  of  mimic 


FIG.  16. — Explosion  in  a  Coal  Mine. — A  rush  for  life. 

lightning,  with  this  difference,  the  light  flashed  up  to 
the  roof  and  assumed  the  mushroom  shape,  but  it  did  not 
disappear.  ...  It  continued  extending  and  spreading 
along  the  roof  on  every  side."  All  the  men  rushed  panic- 
stricken  from  the  extending  light.  There  was  no  diffi- 
culty in  finding  the  way,  the  whole  place  being  illuminated 
by  the  burning  gas.  Looking  back,  the  terrified  miners 
saw  the  whole  gallery  "  one  body  of  fire — not  a  bright 

1  Half-hours  Underground  (Daldy,  Isbister  &  Co.),  p.  226. 


204     MODERN  CHEMISTRY  AND   ITS  WONDERS 

lambent  blaze,  but  lurid,  reddish  volumes  of  flame,  rolling 
on  like  billows  of  fiery  mist."  The  fire  rolled  silently 
forward  hardly  faster  than  a  man  could  run.  There  was 
no  noise  or  sound  of  an  explosion,  one  wave  of  flame 
tumbling  rapidly  over  the  other.  Rushing  to  a  lofty 
passage  the  men  flung  themselves  on  their  faces  on  the 
ground  and  awaited  the  approach  of  the  wall  of  fire 
which  swept  into  sight  out  of  the  side  gallery,  sending 
the  glare  of  its  light  before  it.  The  flame  filled  the  whole 
mouth  of  the  side  of  the  gallery  from  top  to  bottom, 
but  "when  it  entered  the  larger  gallery  it  lifted,  just  as 
one  sees  mist  lifting  on  the  mountains,  and  then  rolled 
along  the  roof,"  passing  over  the  men's  heads,  leaving 
a  space  of  two  or  three  feet  free  from  flame.  They  lay 
under  this  fiery  furnace  for  some  minutes,  when  it  rolled 
away,  eddying,  curling,  and  streaming  about  the  roof. 

Rapidly  rising,  the  men  rushed  down  a  side  passage 
and  reached  a  well-ventilated  part  of  the  mine  and  thus 
escaped  death  by  the  "  choke-damp  "  which  follows  in  the 
wake  of  the  fiery  blast.  Although  the  flame  thus  passed 
quietly  over  the  men,  it  gathered  speed  as  it  went  and 
burst  with  such  violence  up  the  shaft  as  to  blow  the  roof 
off  the  building  over  it.  In  bad  gas  explosions  a  mighty 
column  of  flame  and  smoke  has  been  known  to  shoot  up 
the  pit-mouth,  hurling  the  buildings  situated  there  into  the 
air  with  a  thunder-like  concussion  which  is  heard  for  miles 
around. 

But  you  must  not  think  that  it  is  only  the  methane 
which  is  responsible  for  the  terrible  explosions  which 
occur  in  coal  mines.  For  the  fine  coal  dust  floating 
thickly  in  the  air  is  caught  in  the  advancing  flame,  burns 
instantly,  and  of  itself  causes  a  terrible  explosion.  When 
we  recollect  that  flour  mills  have  been  blown  to 
pieces  by  explosions  caused  by  the  rapid  burning  of  flour 
dust  floating  in  the  air,  and  that  it  is  dangerous  to  enter 


ROMANCE  OF  THE  HYDROCARBONS  205 

them  with  a  naked  light,  it  is  no  wonder  that  coal  dust, 
which  evolves  far  more  heat  in  burning,  can  also  cause 
and  propagate  explosive  waves.     Indeed  in  modern  mines 
the  ventilation  is  so  good  that  methane  scarcely  has  the 
chance   to   collect   anywhere    in    bulk.       It    now   merely 
starts  the  explosive  wave,  and  coal  dust  does   the  rest. 
This,    however,    was    formerly    not    the    case    and    real 
explosions  entirely   caused    by   methane  were    common. 
In  the  year  1856  an  explosion  took  place  in  the  Cymmer 
coal  pit  and  killed   110   men.     In   1857  a  similar  acci- 
dent swept    170  men  into  eternity.      In    1858    methane 
levied  a  contribution  of  215  victims  in  the  coal  pits  of 
England  alone.     In  1866  the  fire  damp  explosion  at  the 
Oaks  Colliery  swept  away  the  appalling  number  of  361 
lives.      Naturally,  after  this   elaborate    precautions   were 
taken  to  prevent  the  accumulation  of  methane  in  mines 
and  excellent  systems  of  ventilation  were  adopted.     Yet 
this  did  not  stop  the  drain  of  life.     Thus  in   1878,  578 
men  lost  their  lives,  in  1880,  480,  while  in  1894  a  single 
explosion  in  a  South  Wales  colliery  swept  away  290  men 
and  boys.     Perhaps  the  most    terrible  explosion    of    all 
occurred    in    1905   in    the   Courrieres    mine    in    France, 
when  1100  men  and  boys  were  killed,  and  this  in  a  mine 
quite  free  from  methane  !     The  awful  toll  of  human  life 
has  slowly  taught  men  that  even  when  methane  is  elimin- 
ated from  mines,  explosions  will  still  occur,  and  that  the 
coal  dust  floating  in  the  air  is  the  agent  which  causes 
them. 

And  yet,  strange  as  it  may  at  first  sight  appear,  it  is 
not  the  fiery  shattering  blast  that  causes  the  greatest  loss  of 
life.  The  unfortunate  miners  may  escape  being  shattered 
to  pieces  against  the  rugged  walls  of  the  mine,  or  being 
scorched  and  shrivelled  to  a  blackened  mass ;  for  the 
flames  may  pass  over  them  if  they  fall  flat  on  their  faces 
on  the  ground,  rushing  above  them  without  harming  them. 


2o6     MODERN  CHEMISTRY  AND   ITS  WONDERS 

But  the  moment  they  rise,  they  feel  about  their  faces  a 
mass  of  red-hot  air  and  dust,  and  it  is  as  if  they  have 
thrust  their  heads  into  a  cauldron  of  molten  lead. 

It  scorches  and  blisters  the  skin  from  their  faces,  and 
the  agony  makes  them  fall  writhing  upon  the  ground  again. 
Now  it  is  a  curious  fact  that  often  the  fiery  blast  rushes 
along  the  roof  and  leaves  the  air  on  the  ground  cool  and 
breathable.  The  second  fall,  therefore,  may  prolong  the 
lives  of  the  miners,  but  only  for  a  short  time.  For  in  the 
track  of  the  flame  comes  death,  invisible  and  intangible, 
not  with  the  roar  of  thunder  and  the  glare  of  flame,  but 
silently,  stealing  through  the  roadways  at  the  tail  of  the 
blast.  It  is  the  poisonous  "after-damp."  Discovering 
themselves  unhurt,  the  miners  who  have  escaped  the 
blast,  rise  and  rush  back,  thinking  to  get  out  of  the  pit 
by  another  way.  All  those  miners  not  in  the  direct  path 
of  the  blast — sometimes  hundreds  of  men — make  a  wild 
rush  for  safety.  But  death,  too,  overtakes  them  as  they 
go.  They  begin  to  feel  sleepy  and  tired  as  they  run. 
The  mysterious,  invisible  "  after-damp "  has  crept  into 
their  lungs,  and  the  men  see  first  the  boys  fall  on  their 
knees  and  mumble  that  they  are  sleepy.  The  men  catch 
them  up  in  their  arms  to  bear  them  into  safety,  and  they 
too  fall  sleepy,  and  drop  with  their  burdens  into  the  dust, 
and  fall  asleep  likewise.  Dead,  all  dead — the  after-damp 
has  caught  them.  They  will  have  no  bruises,  and  their 
cheeks  will  be  rosy  under  the  black  coal  dust,  their 
features  placid  and  peaceful.  The  after-damp  deals  a 
painless  and  easy  death.  Plate  22  shows  men  thus  killed. 

The  poor  miners  caught  in  an  exploded  pit  thus  run 
two  chances  of  death — one  from  burning,  and  the  other 
from  being  rendered  insensible  by  after-damp.  Whether 
death  is  caused  by  the  one  agent  or  by  the  other  may  be 
easily  read  in  the  faces  of  the  dead.  The  men  killed  by 
the  flame  are  marked  with  burns  and  scorching,  and  their 


Photo  by  Trost. 

PLATE  21. — A  fifty-thousand  barrel  storage  tank  for  petroleum  in  course 
of  construction. 


PLATE  22. — Dead  miners,  overcome  by  carbon  monoxide  ("  after-damp  "),  after  a 
coal-mine  explosion  at  Pennycraig. 

About  75%  of  miners  killed  in   coal-mine  explosions  die  as  the  result  of  carbon 
monoxide  poisoning. 


ROMANCE  OF  THE  HYDROCARBONS  207 

features  are  more  or  less  distorted  or  disfigured.  On  the 
other  hand  men  killed  by  choke-damp  lie  as  if  sleeping, 
their  faces  placid,  and  their  clothes  unmarked  by  fire. 
Of  the  two  death-dealing  agencies,  the  after-damp  is  the 
far  more  deadly.  Out  of  four  men  killed  in  a  mine 
explosion  no  less  than  three  will  die  peaceably  under  the 
influence  of  the  after-damp.  For  the  vast  force  of  the 
explosion  often  shatters  the  galleries  and  destroys  the 
means  of  ventilating  them.  When  this  occurs  there  is 
an  end  to  all  hope  of  safe  retreat  even  for  men  totally 
uninjured  by  the  flames.  The  after-damp  formed  at  once 
exerts  its  full  effect,  and  those  who  cannot  rush  to  the 
shaft  are  suffocated.  In  the  explosion  at  Risca  it  was 
found  that  of  those  killed  no  less  than  70  per  cent, 
died  from  the  effects  of  after-damp,  men  who  had  not 
been  near  the  fire  at  all.  In  the  great  Haswell  explosion 
seventy-one  deaths  out  of  ninety-five  were  caused  by  it. 
It  may  be  taken  as  proved  that  at  least  70  per  cent, 
of  the  deaths  in  fiery  mines  are  due  to  after-damp. 

What,  then,  is  this  tf  after-damp  "  ?  Let  me  explain. 
When  a  gas  like  methane  burns  in  an  abundance  of  air, 
it  burns  to  carbon  dioxide,  thus : — 

CH4    +    202     =     C02     +     2H20 

Methane        Oxygen        Carbon  dioxide        Water 

But  in  the  depths  of  mines  there  is  usually  not  enough 
air  to  supply  sufficient  oxygen  for  complete  combustion, 
and  so  another  and  very  poisonous  oxide  of  carbon  is 
formed,  called  carbon  monoxide.  Carbon  dioxide  is  not 
of  itself  very  poisonous,  and  the  percentage  formed  in  the 
air  after  an  explosion  is  seldom  sufficient  to  suffocate. 
It  is  a  smaller  percentage  of  the  deadly  carbon  monoxide 
produced  which  does  the  damage  and  renders  the  ^after- 
damp "  so  poisonous.  Before  going  on,  then,  to  discuss 
the  precautions  suggested  by  science  for  preventing  ex- 


208     MODERN   CHEMISTRY  AND  ITS  WONDERS 

plosions,   I   will  first  of  all  say  a  few  words  about  this 
remarkable  gas. 

All  of  you  must  have  read  of  those  terrible  tragedies 
which  occur  from  time  to  time  in  every  country.  Men, 
yes,  and  women  too,  have  gone  voluntarily  to  their  death 
because  they  have  found  the  conditions  of  life  intolerable. 


FIG.  17. — Death  from  carbon  monoxide  poisoning. 

For  many  centuries  on  the  continent,  and  especially  in 
France,  a  method  has  been  practised  for  passing  into 
eternity  which  at  first  sight  might  strike  one  ignorant  of 
the  science  of  chemistry  as  very  remarkable.  A  room  is 
chosen.  Every  crack  in  door,  window,  or  fireplace  is 
most  carefully  closed  up.  Then  a  charcoal  fire  is  lighted 
in  the  middle  of  the  room,  in  just  such  a  brazier  as  you 
may  see  in  the  streets  at  night  when  the  roads  are  under- 


ROMANCE  OF  THE  HYDROCARBONS  209 

going  repair.  The  charcoal  burns,  emitting  poisonous 
fumes.  Soon  a  deadly  sleepiness  steals  over  the  victim. 
His  head  nods,  his  eyes  shut,  and  he  gradually  sinks  into 
a  deep  terrible  slumber  and  passes  slowly  away.  "Ah  !" 
you  will  say,  "the  explanation  is  simple  enough.  The 
victim  has  been  overcome  by  the  carbon  dioxide  evolved 
from  the  burning  charcoal."  But  this  is  not  so.  People 
killed  by  carbon  dioxide  have  been  suffocated.  They 
have  died  not  because  the  carbon  dioxide  is  poisonous, 
but  because  of  lack  of  oxygen  in  the  surrounding  air. 
Their  blood  turns  dark  purple,  the  colour  of  venous  blood 
requiring  oxygen,  and  their  faces  and  lips  assume  a 
horrible  bluish  tint.  But  look  at  a  victim  killed  by  the 
charcoal  fumes  !  His  lips  and  cheeks  are  vivid  pink,  far 
pinker  than  they  ever  were  in  life.  His  blood,  too,  is 
not  of  a  dark  venous  colour  ;  it  also  is  bright  pink.  We 
are  dealing  with  no  case  of  suffocation  here.  The  man 
has  not  died  as  the  result  of  the  action  of  carbon  dioxide. 
We  are  witnessing  the  effects  of  another  poisonous  gas — 
a  substance  far  more  deadly  than  carbonic  acid.  What 
can  this  gas  be  ?  Since  it  has  been  evolved  from  burning 
charcoal — which  is,  practically,  pure  carbon — the  reader 
will  at  once  jump  to  the  conclusion  that  it  is  another  com- 
pound of  carbon  and  oxygen,  an  oxide  different  from  carbon 
dioxide.  And  quite  correctly,  too.  The  gas  is  well  known 
to  chemists  under  the  name  Carbon  monoxide  or  Carbonic 
oxide  and  possesses  the  formula  CO.  Its  formation  in  a 
charcoal  fire  is  also  well  understood.  Indeed  it  may  be  pre- 
pared in  a  practically  pure  state  by  passing  oxygen  or  carbon 
dioxide  through  a  long  layer  of  charcoal  placed  in  an  iron 
tube  and  heated  red  hot  in  a  fire.  The  action  is  as  follows: 
the  oxygen  first  attacks  the  carbon  in  the  outermost  layers, 
and  burns  them  in  the  usual  way  to  carbon  dioxide,  thus  : 
C  +  02  =  C02 

Carbon       Oxygen       Carbon  dioxide 


210     MODERN  CHEMISTRY  AND  ITS  WONDERS 

The  carbon  dioxide  then,  passing  on  into  the  red-hot 
charcoal,  takes  up  more  carbon  and  becomes  carbon 
monoxide,  thus : 

CO2       +      C      =         2CO 

Carbon  dioxide       Charcoal      Carbon  monoxide 

The  beautiful  blue  flames  hovering  above  a  clear  coal 
fire  are  due  to  burning  carbon  monoxide  produced  in  this 
way.  Death,  therefore,  lurks  in  the  gases  ascending  from 
every  clear  fire,  though  we  seldom  realise  this  as  we 
watch  the  smoke  rapidly  ascending  the  chimney  from  a 
comfortable  red  coal  fire  burning  merrily  in  a  grate. 

The  gas  thus  prepared,  although  invisible  and  colour- 
less, differs  very  much  in  properties  from  carbon  dioxide. 
Thus,  carbon  dioxide  is  very  soluble  in  water,  but  carbon 
monoxide  hardly  dissolves  at  all.  Carbon  dioxide  is  a 
heavy  gas,  1 J  times  heavier  than  air  ;  but  carbon  monoxide 
has  almost  exactly  the  same  density  as  air.  Carbon 
dioxide  is  a  dead  inert  gas  which  will  not  burn  ;  carbon 
monoxide,  however,  burns  with  a  beautiful  blue  flame, 
producing  carbon  dioxide,  thus  : 

2CO         +    O2    =      2CO2 

Carbon  monoxide      Oxygen      Carbon  dioxide 

Its  remarkably  poisonous  action  depends  upon  the 
fact  that  it  combines  with  the  blood  in  much  the  same 
way  that  oxygen  does,  turning  it  a  light  red  colour  ;  and 
this  explains  the  peculiar  pink  colour  of  the  lips  and 
cheeks  of  men  who  have  lost  their  lives  by  breathing  it. 
Blood  so  attacked  cannot  absorb  oxygen  and  so  becomes 
useless  as  a  means  for  conveying  oxygen  into  the  system. 
Dr.  Leonard  Hill  thus  describes  its  physiological  action : l 

"  Carbon  monoxide  chemically  combines  with  the 
haemoglobin  of  the  blood,  and  destroys  life  by  robbing 

1  Lecture  delivered  at   the    North   Staffordshire   Institute   of  Mining   and 
Mechanical  Engineers,  January  13,  1908. 


ROMANCE  OF  THE  HYDROCARBONS  211 

the  body  of  oxygen,  which  is  normally  carried  by  the 
haemoglobin.  The  gas  is  not  a  poison  except  in  so  far 
as  it  is  an  oxygen-robber.  This  is  proved  by  the  fact 
that  animals  poisoned  by  the  gas  can  be  kept  alive  and 
vigorous  on  two  atmospheres  of  pure  oxygen,  for  then 
enough  oxygen  is  dissolved  in  the  blood  plasma  to  main- 
tain life  independently  of  the  oxygen-carrying  function  of 
the  haemoglobin.  If  blood  be  shaken  with  air  containing 
0-07  per  cent.  CO  and  21  per  cent.  O2,  the  haemoglobin  is 
found  to  be  equally  shared  between  the  two  gases.  Thus 
carbon  monoxide  has  an  affinity  for  haemoglobin  300 
times  that  of  oxygen.  When  the  blood  is  20  per  cent, 
saturated  with  carbon  monoxide  there  occurs  dizziness 
and  shortness  of  breath  on  exertion.  The  symptoms  are 
exaggerated  by  increasing  saturation  in  a  very  insidious 
and  dangerous  manner,  there  being  little  sense  of  dis- 
comfort to  warn  the  subject  of  the  increasing  failure  of 
his  mental  and  physical  powers.  At  50  per  cent,  satura- 
tion it  is  scarcely  possible  to  stand,  and  the  slightest 
exertion  causes  temporary  loss  of  consciousness.  Exertion 
by  using  up  the  oxygen  in  the  muscles  hastens  the  failure 
of  the  heart's  action  ;  there  may  result  degenerative  changes 
in,  and  lasting  weakness  of  the  heart  in  those  rescued 
from  death.  It  is  important  to  remember  that  the  ex- 
posure of  the  sufferer  to  cold  fresh  air  aggravates  the 
symptoms,  and  may  be  fatal.  The  heart  requires  all  the 
available  oxygen,  and  to  that  end  the  body  must  be  kept 
warm  by  external  heat,  so  that  no  demand  is  made  on 
the  heat-producing  (oxidative)  mechanism  of  the  body. 
The  tube  from  an  oxygen  cylinder  should  be  allowed  to 
play  into  the  sufferer's  mouth  for  at  least  a  quarter  of  an 
hour,  and  artificial  respiration  given  if  necessary.  If 
breathing  be  re-established  properly,  all  danger  from  the 
CO  in  the  blood  is  over  at  the  end  of  an  hour.  Prolonged 
nursing  may  be  required  to  steer  the  patient  through 


212      MODERN  CHEMISTRY  AND   ITS  WONDERS 

the  subsequent  fatty  degenerations  of  the  tissues  which 
may  result." 

Perhaps  the  best  way  to  bring  back  to  life  men  or 
animals  poisoned  by  the  gas,  is  to  pump  pure  oxygen  into 
their  lungs  under  pressure.  The  dying  unconscious 
victims  are  placed  in  an  air-tight  box  and  pure  oxygen 
gas  is  pumped  in  until  the  pressure  reaches  two  atmo- 
spheres. In  the  presence  of  so  much  oxygen  animals 
can  breathe  gas  containing  no  less  than  6  per  cent,  of  the 
poisonous  carbon  monoxide.  Under  ordinary  circum- 
stances 0'15  per  cent,  of  this  gas  in  the  air  is  very 
dangerous,  and  0*4  per  cent,  practically  always  causes 
death.  What  makes  the  presence  of  carbon  monoxide  in 
air  so  extremely  dangerous  is  the  fact  that  it  gives  no 
indications  of  its  presence  until  the  fatal  symptoms  begin 
to  appear.  For  not  only  is  the  gas  colourless  and  odour- 
less, but  the  continuous  breathing  of  such  a  small  amount 
as  1  part  in  10,000  of  air  may  kill  the  unsuspecting 
victim.  The  best  test  for  the  gas  is  a  small  mouse  carried 
in  a  cage.  This  becomes  paralysed  by  carbon  monoxide 
long  before  a  man  is  affected,  and  so  gives  timely  warning 
of  the  poisonous  state  of  the  air. 

How  many  victims  have  been  claimed  by  this  sub- 
stance in  past  years  will  now  never  be  known.  The 
number,  however,  must  be  very  great.  Every  case  of 
poisoning  by  ordinary  coal  gas  is  due  to  carbon  monoxide, 
which  is  present  in  coal  gas  to  the  extent  of  5  to  12  per 
cent.  The  gas  is  produced  in  large  quantities  when 
carbonaceous  matter  burns  in  places  where  there  is  not 
sufficient  oxygen  for  complete  combustion.  Thus  after 
a  mine  explosion,  when  a  flash  of  flame  sweeps  through 
the  underground  passages,  the  coal  dust  in  the  air  is  not 
completely  burnt  up  and  a  large  amount  of  carbon 
monoxide  is  produced  which  renders  the  entry  to  such 
exploded  pits  so  very  dangerous. 


ROMANCE  OF  THE  HYDROCARBONS  213 

It  was  carbon  monoxide  which  caused  the  tragic 
death  of  the  great  French  writer  Zola  in  1902.  He  and 
his  wife  had  just  returned  to  their  home  in  Paris  after  a 
visit  to  the  country.  They  dined  together  and  went  to 
bed  early,  their  two  little  dogs  being  installed  in  an 
armchair  in  the  bedroom.  Now  unknown  to  them  a  fire 
had  been  lighted  in  a  stove  in  their  room  and  through 
some  accident  the  chimney  had  become  blocked  up. 
The  charcoal  burning  in  the  limited  space  began  to  pro- 
duce carbon  monoxide  and  dioxide.  The  gas  produced  a 
splitting  headache  in  Madame  Zola  and  she  woke  up  and 
begged  her  husband  to  get  out  of  bed  and  open  the 
window.  He,  waking  out  of  an  uneasy  sleep,  at  once 
got  out  of  bed,  but  the  slight  exertion  caused  him  to  lose 
consciousness,  and  he  fell  in  a  heap  on  the  floor.  Madame 
Zola  then  fainted  and  so  could  not  summon  assistance. 
Next  morning  the  servant  knocked  on  the  door.  She 
received  no  answer.  She  listened.  Within  reigned  a 
deathlike  silence.  Horrified,  she  summoned  the  other 
servants.  They  assembled  round  the  door  and  beat 
upon  it.  Still  no  answer.  Now  thoroughly  alarmed 
they  burst  it  open.  A  horrible  sight  met  them.  Zola 
lay  dead  on  the  floor,  while  Madame  Zola,  still  faintly 
breathing,  lay  in  a  swoon  across  the  bed.  She  subse- 
quently recovered,  as  did  the  two  little  dogs. 

But  a  far  more  terrible  disaster  than  this  happened 
on  May  10,  1897,  in  a  lead  mine  on  the  Snaefell  mountain 
in  the  Isle  of  Man.  Somehow  or  other — the  exact  cause 
was  never  ascertained — some  of  the  timbers  supporting 
the  mine  roof  caught  fire  late  on  a  Saturday  evening 
when  the  mine  was  deserted. 

The  mass  of  timber,  burning  in  a  very  limited  supply 
of  air,  soon  filled  the  mine  with  a  mixture  of  carbon 
monoxide  and  dioxide.  It  continued  to  burn  all  Sunday 
unknown  to  everyone.  On  Monday  morning  at  6  A.M. 


2i4     MODERN  CHEMISTRY  AND  ITS  WONDERS 

a  band  of  35  miners,  quite  unsuspecting  the  death  which 
awaited  so  many  of  them  below,  entered  the  mine  shaft 
and  began  to  climb  down  into  its  dark  depths.  It  is  easy 
to  imagine  the  men,  each  with  a  little  light  on  his  head 
illuminating  the  darkness  around,  steadily  climbing  down- 
wards, ladder  after  ladder,  laughing  and  making  rough 
jokes  as  they  went.  Suddenly  the  lower  men  began  to 
feel  peculiar.  Everything  whirled  about  them,  and  they 
fell  one  after  the  other  unconscious,  until  14  bodies  were 
stretched  lifeless  on  the  platforms  below.  The  men  still 
coming  down,  seeing  the  fate  of  those  below  them,  cried 
out  warning  to  those  above,  and  commenced  to  ascend 
for  their  lives.  But  the  insidious  poison  now  began 
to  work  upon  them  also.  Their  limbs  grew  numb  and 
weak,  and  many  fainted  and  had  to  be  supported  by  their 
comrades.  Some,  indeed,  were  left  behind  and  were 
found  later  in  a  dying  condition.  Finally  there  staggered 
out  of  the  shaft  a  few  exhausted  men  who  said  that  the 
mine  was  full  of  some  foul  gas  which  made  them  so 
weak  that  they  could  scarcely  climb  the  ladders.  The 
news  that  a  great  disaster  had  happened  spread  like 
wildfire  and  telegrams  were  soon  flashing  all  over  the 
country  summoning  help.  Soon  rescue  parties  were  on 
the  spot  and  began  to  descend  and  drag  out  the  dead 
and  dying  miners  by  means  of  ropes.  But  the  poisonous 
gases  began  to  act  upon  the  rescuers  themselves  and 
they  too  became  weak  and  paralysed  and  were  forced 
to  beat  a  retreat.  Meanwhile  the  great  engines  above 
were  driving  compressed  air  into  the  mine,  which  dis- 
placed the  poisonous  gases  and  bettered  the  condition  of 
the  shaft  from  hour  to  hour.  The  rescuers  soon  de- 
scended again  and  succeeded  this  time  in  recovering  all 
the  bodies  except  one  which  lay  at  a  still  lower  level. 
They  soon  had  worked  their  way  down  to  a  platform 
some  780  feet  below  the  surface,  and  through  a  manhole 


ROMANCE  OF  THE  HYDROCARBONS  215 

in  this  they  could  see  dimly  the  body  of  the  last  man 
lying  ten  feet  below.  To  view  this  better  one  of  the 
miners  put  a  light  through  the  manhole  but  it  went  out, 
showing  that  the  space  below  was  still  filled  with  un- 
breathable  gas.  The  leader  of  the  rescuing  expedition, 


FIG.  18. — The  Snaefell  disaster — bringing  up  miners  overcome  by 
carbon  monoxide. 


Mr.  Williams,  now  endeavoured  to  collect  samples  of  the 
air  below  the  platform.  This  he  accomplished  by  hold- 
ing a  bottle  full  of  water  under  it,  allowing  the  water  to 
run  out,  and  then  recorking  it.  He  had  already  obtained 
two  samples  in  this  way  when  suddenly,  without  any 
preliminary  warning,  the  men  above  saw  him  fall  uncon- 
scious. He  would  beyond  all  doubt  have  perished  there 


216     MODERN  CHEMISTRY  AND   ITS  WONDERS 

and  then  had  he  not,  luckily,  been  supported  by  a  rope 
around  his  waist.  As  it  was  the  men  dragged  his  uncon- 
scious body  by  means  of  this  rope  up  from  platform  to 
platform  for  a  distance  of  eighty  feet,  and  then  placed  his 
mouth  to  a  hole  punched  in  a  compressed  air  pipe,  and 
applied  artificial  respiration.  These  prompt  measures 
saved  his  life.  Mr.  Williams,  relating  his  experiences 
later,  described  how  first  he  discerned  a  strong  disagreeable 
smell  arising  from  below.  "  My  next  sensation  was  in- 
describably pleasurable,  and  one  which  I  wished  to  last 
for  ever,  for  as  it  passed  away,  and  I  recovered  conscious- 
ness, I  ungratefully  said  to  Dr  Miller,  '  Why  did  you  not 
let  me  die  ? ' '  Afterwards  a  painful  headache  set  in  which 
lasted  for  some  days.1 

The  late  Dr.  Le  Neve  Foster,  who  formed  one  of  the 
rescuing  party,  thus  describes  the  paralysing  action  of 
carbon  monoxide: — 

"  The  poison  took  effect  most  suddenly.  Everything 
seemed  in  a  whirl  and  the  atmosphere  seemed  to  be  a 
dense  white  fog.  ...  It  is  a  curious  fact  that  we  all  sat 
without  moving  or  trying  to  escape ;  the  foot  of  the 
ladder  was  close  by,  yet  none  of  us  made  any  effort  to  go 
to  it  and  ascend  even  a  single  rung.  We  none  of  us 
tried  to  walk  a  dozen  steps,  which  would  have  led  us  to 
the  other  side  of  the  shaft  partition,  where  we  all  knew 
there  was  a  current  of  better  air.  We  simply  sat  on  and 
on,  rooted  to  our  seats.  .  .  .  The  general  sensation  was 
like  a  bad  dream." 

This  unfortunate  gentleman  never  really  recovered 
from  the  effects  of  breathing  such  a  large  quantity  of 
poisonous  gas,  and  a  year  or  two  afterwards  succumbed 
to  a  malady  which  is  believed  to  have  directly  arisen  from 
this  experience. 

1  See  Foster  and  Haldane's  Textbook  on  Mining  Chemistry. 


ROMANCE  OF  THE  HYDROCARBONS  217 

The  reader  must  not  look  upon  this  gas  as  utterly 
bad.  It  has  its  good  properties  too  ;  like  fire,  it  makes  a 
very  bad  master  but  a  good  servant.  For  example,  it  is 
a  splendid  fuel,  giving  forth  an  intense  heat  when  burning 
to  carbon  dioxide,  CO  +  O  =  CO9.  Indeed  the  fierce 


FIG.  19. — Principle  of  a  safety  lamp — a  flame  will  not  pass  through 
wire  gauze. 


heat  of  many  of  the  furnaces  which  redden  the  sky  at 
night  of  manufacturing  districts,  is  often  largely  due  to 
the  use  of  this  gas  as  fuel.  The  avidity  with  which  it 
combines  with  oxygen  and  removes  this  element  from 
metallic  ores  makes  it  a  valuable  reducing  agent  for 
obtaining  metals  from  their  ores.  Under  the  name 
"  water  gas "  it  drives  many  a  powerful  gas  engine,  it 


218     MODERN  CHEMISTRY  AND  ITS  WONDERS 

being  in  this  case   produced    by   driving  steam  through 
tall  cylinders  filled  with  white-hot  coke : 

C   +H20=         CO          +     H2 

Coke      Steam      Carbon  monoxide       Hydrogen 

As  thus  produced  it  is  mixed  with  half  its  volume  of 
hydrogen. 

Let  us,  however,  now  return  to  the  subject  of  mine 
explosions. 

Naturally  many  attempts  have  been  made  to  overcome 
the  terrors  of  explosive  gases  in  mines.  These  attempts 
depend  upon  the  fact  that  a  burning  flame  will  not  go 
through  fine  metal  gauze.  Every  gas  must  be  raised  to  a 
definite  temperature  before  it  will  burn.  For  example, 
a  mixture  of  methane  and  oxygen  will  not  inflame  below 
a  red  heat.  Conversely,  if  the  burning  gas  is  cooled 
below  a  red  heat  it  ceases  to  burn.  Now  when  a  flame 
of  burning  gas  reaches  wire  gauze,  the  gauze  takes  away 
its  heat  so  rapidly,  conducting  and  radiating  it  into  space, 
that  the  gas  passing  through  is  cooled  below  the  tempera- 
ture necessary  to  make  it  burn.  Hence  the  flame  is 
quenched  when  it  reaches  the  gauze,  only  a  stream  of 
unburnt  gas  passing  through. 

If  now  we  surround  the  flame  of  an  ordinary  oil- 
lamp  on  every  side  with  gauze,  and  introduce  it  into  the 
midst  of  an  explosive  gaseous  atmosphere,  all  that  will 
happen  is  that  the  gas  actually  inside  the  gauze  will  take 
fire  and  burn,  but  the  flame  will  not  pass  through  the 
gauze  and  set  alight  the  gas  outside.  This,  in  fact,  is 
Sir  Humphry  Davy's  celebrated  "  safety  lamp."  When 
the  miner  armed  with  this  enters  an  explosive  atmosphere 
the  lamp  warns  him  of  impending  danger  by  enlarging  its 
flame.  A  blue  light  fills  the  space  within  the  metal  gauze, 
but  as  if  chained  by  some  magic  power  the  flame  is 
unable  to  pass  beyond  and  ignite  the  tremendous  mass 


ROMANCE  OF  THE  HYDROCARBONS  219 

of  gas  waiting  to  explode  outside.  "  Just  as  we  view  in 
safety  fierce  beasts  behind  their  iron  gratings  in  a 
menagerie,  so,  too,  the  miner  looks  calmly  upon  his 
terrible  foe  imprisoned  within  its  flimsy  cage  of  iron 
gauze."  Yet  even  this  lamp  is  not  quite  safe.  If  the 


FIG.  20.— Davy's  safety  lamp. 

flame  impinges  too  long  upon  the  wire  it  may  render  it 
red  hot  and  this  will  then  ignite  the  gas  outside.  Even 
the  rapid  motion  produced  by  the  swing  of  the  arm  when 
walking  may  produce  explosion.  Blowing  out  the  light 
is  likewise  attended  with  danger,  as  the  flame  may  be 
driven  through  the  gauze  and  spread  terror  and  death 
around.  Nevertheless  the  introduction  of  the  safety  lamp 
has  undoubtedly  preserved  the  lives  of  many  miners  and 


220     MODERN  CHEMISTRY  AND   ITS  WONDERS 

has  certainly  prevented  many  serious  accidents.  For 
example,  in  the  Walker  Colliery  on  the  Tyne  a  bore-hole 
having  been  made,  a  roar  like  the  blowing  off  of  steam 
was  heard  by  the  drillers,  and  a  heavy  discharge  of  gas 
filled  the  air  courses  for  a  distance  of  1900  feet.  At  a 
distance  of  a  quarter  of  a  mile  from  the  scene  of  the 
outbreak  a  mining  official  met  the  rush  of  foul  air  and 
saw  the  safety  lamp  in  his  hand  enlarge  its  flame.  He 
at  once  drew  down  the  wick  and  put  it  out,  but  his  feelings 
may  be  imagined  when  he  saw  the  gas  in  the  lamp  still 
continuing  to  burn,  making  the  wires  red  hot  and  threaten- 
ing at  any  instant  to  pass  through  and  ignite  the  gas 
outside.  Had  it  done  so  a  great  disaster  would  have 
taken  place,  as  there  were  hundreds  of  men  working  in 
the  pit  at  the  time.  With  a  sigh  of  relief  he  saw  the 
burning  gas  inside  flicker  and  go  out,  leaving  him  in 
darkness.  Groping  his  way  forward  as  rapidly  as  possible, 
he  came  upon  four  men  and  two  boys  200  yards  further 
on  whose  lamps  were  rapidly  reddening.  He  shouted 
warning,  and  they  had  the  presence  of  mind  to  plunge 
them  into  water  and  thus  avoid  all  danger  of  explosion. 

Our  ordinary  coal  gas  contains  much  methane,  and  is 
prepared  by  heating  coal  in  retorts.  Heat,  in  fact,  here 
accelerates  an  action  going  on  very  slowly  at  ordinary 
temperatures  in  coal  beds.  Besides  30-40  %  of  methane, 
coal  gas  contains  45-57  %  of  hydrogen,  5-12  %  of  carbon 
monoxide,  and  small  quantities  of  other  substances. 

Pure  methane  may  be  prepared  by  merely  throwing 
aluminium  carbide  into  warm  water. 

The  usual  method  of  preparing  the  substance  in  the 
laboratory,  however,  is  by  heating  together  in  a  copper 
flask  sodium  acetate  and  soda  lime. 

Another  very  remarkable  and  important  gas  is : 

Acetylene,  C2H2.  This  is  also  colourless,  and  it 
possesses  when  pure  a  pleasant  ethereal  odour,  but,  as 


ROMANCE  OF  THE  HYDROCARBONS  221 

usually  prepared,  is  accompanied  by  evil  smelling  im- 
purities. The  gas  is  poisonous  and  may  be  easily  pro- 
duced by  merely  throwing  calcium  carbide  into  water  : 

CaC2       +  2H20  =   C2H2  +  Ca(OH)2 

Calcium  carbide        Water        Acetylene      Slaked  lime 

In  a  suitable  burner  the  gas  burns  with  an  indescrib- 
ably brilliant  flame,  which  almost  rivals  that  of  the  electric 
arc,  and  for  this  reason  has  been  employed  for  bicycle 
lamps,  and  for  lighting  up  places  where  coal  gas  is  not 
available — such  as  small  villages,  country  houses,  and 
railway  stations.  When  calcium  carbide,  CaC2,  began  to 
be  manufactured  very  cheaply,  about  1892,  naturally 
acetylene  gas  also  became  very  cheap,  and  some  firms 
began  to  sell  it  in  a  liquid  form  for  illuminating  purposes. 
This  could  easily  be  done,  for  the  gas  liquefies  at  the 
melting  point  of  ice  under  a  pressure  of  21^  atmospheres. 
All  this  time  these  men  were  unwittingly  handling  a  stuff 
which  can  explode  with  a  force  comparable  to  that  of 
gun-cotton  !  A  terrible  accident  revealed  this  fact  to  the 
world.  In  1896  at  the  Paris  Works  of  Raoul  Pictet 
two  workmen  were  handling  one  of  these  cylinders  filled 
with  compressed  acetylene.  They  were  in  a  building  with 
walls  over  30  feet  high,  situated  at  the  back  of  the  main 
factory,  and  separated  from  it  by  a  courtyard.  Suddenly 
the  inmates  of  the  main  factory  were  startled  by  a 
thunder-like  explosion,  which  shook  the  earth  and  broke 
all  the  glass  windows  in  the  neighbourhood.  Rushing 
out  in  a  panic  a  terrible  scene  met  their  eyes.  The 
cylinder  of  acetylene  had  exploded  with  incredible  force, 
killing  the  two  men  and  blowing  down  the  walls  of  the 
building  in  which  they  had  been  working.  The  whole 
courtyard  was  strewn  with  fragments  of  masonry  and 
broken  glass.  Near  the  gasometer  was  a  boiler-house, 
and  the  stoker  engaged  there  had  escaped  by  a  miracle, 


222      MODERN  CHEMISTRY  AND  ITS  WONDERS 

although  bleeding  from  cuts  caused  by  flying  splinters  of 
glass.  Had  the  gasometer  of  acetylene  gas  exploded  the 
consequence  would  have  been  far  more  serious. 

Later  investigations  showed  that  acetylene  compressed 
to  over  two  atmospheres  can  be  made  to  explode  by  a 
detonating  fuse,  a  sudden  blow,  or  an  electric  spark, — 
being,  in  fact,  a  very  dangerous  substance.  By  explosion 
it  is  resolved  suddenly  into  its  elements,  thus  : 

C2H2  =    C2    +     H2 

Acetylene      Carbon       Hydrogen 

If  the  pressure  is  below  2  atmospheres  the  gas  will  not 
explode,  but  may  slowly  decompose,  depositing  carbon 
in  the  form  of  a  fine  soot,  and  generating  hydrogen.  For 
this  reason  vessels  filled  with  liquid  acetylene  are  danger- 
ous even  when  decomposition  takes  place  slowly  and  not 
explosively,  for  the  accumulated  pressure  of  the  hydro- 
gen generated  will  finally  shatter  the  stoutest  steel  vessel. 
These  discoveries  killed  for  a  time  the  rising  acetylene 
industry,  and  caused  much  money  to  be  lost  by  those  who 
had  invested  their  capital  in  it. 

We  see,  therefore,  that  an  intense  chemical  energy 
slumbers  in  the  acetylene  molecule,  and  it  is  the  direct 
transformation  of  this  chemical  energy  into  light  energy 
which  causes  the  wonderful  dazzling  brilliancy  of  its 
flame.  Acetylene  is  "  endothermic."  That  is  to  say, 
there  is  heat  locked  up  in  it,  which  energy  is  again  set 
free  when  the  molecule  decomposes.  This  is,  in  part,  the 
reason  why  the  substance  is  explosive. 

The  gas  is  soluble  in  about  its  own  volume  of  water, 
It  is  very  soluble  in  acetone,  which  will  take  up  over  25 
times  its  volume  of  the  gas  at  15°  C.  at  ordinary  pressures, 
and  300  volumes  at  12  atmospheres'  pressure.  It  has 
been  proposed  to  use  the  solution  in  acetone  instead  of 
liquid  acetylene,  as  the  solution  is  non-explosive,  and 
gives  off  a  very  large  volume  of  gas. 


PLATE  23. — Oxy-acetylene  b'.ow-pipe  for  piercing  holes  in  metal  rails. 


ROMANCE  OF  THE  HYDROCARBONS  223 

Advantage  is  taken  of  this  fact  by  the  Acetylene  Illumi- 
nating Co.,  who  employ  light  steel  cylinders  filled  with  a 
baked  porous  material.  The  pores  of  this  material  are 
charged  with  a  known  quantity  of  acetone  after  the 
removal  of  air,  and  the  cylinders  are  then  charged  with 
acetylene  under  pressure.  On  opening  the  cylinder  valves 
the  gas  is  steadily  given  off  until  the  contents  are  ex- 
hausted. Many  motor  buses  are  using  these  cylinders  as 
illuminating  agents,  and  also  railway  men  who  have  to 
work  in  dark  tunnels  use  them  instead  of  the  old  petroleum 
"  flares." 

Another  extensive  use  of  acetylene  is  its  employment  for 
welding  and  cutting  metals.  As  previously  mentioned,  a 
wonderful  amount  of  heat  is  given  out  when  acetylene 
gas  is  burnt,  amounting  to  14,200  calories  per  cubic 
metre,  and  so  an  enormously  hot  flame  is  produced  by 
using  acetylene  instead  of  hydrogen  in  the  oxy-hydrogen 
blowpipe  flame,  the  best  welding  results  being  obtained 
with  1*6  pure  oxygen  to  1  of  acetylene.  The  flame 
thus  produced  has  in  its  centre  a  small  white  cone,  at 
the  apex  of  which  the  temperature  is  about  6000°  F. 
(3300°  C.).  This  flame  consists  almost  entirely  of  carbon 
monoxide,  which  is  being  converted  at  its  extremity  into 
the  carbon  dioxide.  Round  the  flame  is  a  relatively  cool 
jacket  of  hydrogen,  which,  not  being  able  to  combine 
with  oxygen  at  the  very  high  temperature  in  the  immedi- 
ate neighbourhood  of  the  flame,  remains  temporarily  in 
the  free  state,  and  thus  excludes  the  possibility  of  oxida- 
tion, which  makes  the  flame  very  suitable  for  welding. 
In  this  flame  iron  and  the  most  refractory  metals  melt 
and  run  like  water  and  so  can  be  fused  together  into 
homogeneous  masses. 

Another  very  important  use  to  which  the  oxy-acetylene 
blowpipe  flame  is  now  put  to,  is  cutting  and  boring  holes 
in  thick  iron  objects.  An  oxy-acetylene  blowpipe  used 


224     MODERN   CHEMISTRY  AND   ITS  WONDERS 

for  the  purpose  is  shown  in  Plate  23.  First  of  all,  through 
a  jet  A  an  oxy-acetylene  flame  is  made  to  impinge  on  the 
piece  of  iron.  The  latter  is  heated  to  an  enormous 
temperature,  and  while  it  is  thus  heated  oxygen  from 
a  jet  B  is  made  to  play  on  the  heated  surface.  The 
heated  iron  catches  fire  and  burns  away  into  molten  iron 
oxide.  The  jet  of  oxygen  is  made  sufficiently  strong  to 
blow  away  this  liquid  iron  oxide  in  front  of  it,  and  thus 
a  clean  narrow  cut  is  effected  through  the  metal  at  a 
speed  of  travel  as  rapid  as  that  of  hot  sawing.  The 
metal  on  each  side  of  the  cut  is  neither  melted  nor 
injured  in  any  way,  as  the  action  is  too  rapid  for  the 
heat  to  spread,  the  edges  thus  presenting  the  sharp  and 
metallic  surface  of  a  saw-cut. 

The  cutting  may  be  made  to  follow  any  line,  circle 
or  curve.  Thus  when  A  and  B  are  made  to  revolve  a 
circular  hole  is  produced.  In  Plate  24  is  shown  the 
cutting  of  armour-plate  9  inches  thick  with  the  oxy- 
acetylene  flame. 


8. 


Ci 


